Comparative karyotypes of two northeastern Pacific abalone species (Haliotis fulgens Philippi and Haliotis rufescens Swainson).ABSTRACT The karyotypes of 2 northeastern Pacific abalone abalone (ăbəlō`nē), popular name in the United States for a univalve gastropod mollusk of the genus Haliotis, members of which are also called ear shells, or sea ears, as their shape resembles the human ear. species, Haliotis fulgens and H. rufescens, were evaluated from trochophore troch·o·phore n. The small, free-swimming, ciliated aquatic larva of various invertebrates, including certain mollusks and annelids. [Greek trokhos, wheel (from trekhein, larvae Larvae, in Roman religion Larvae: see lemures. cells, finding that for both species the diploid diploid /dip·loid/ (dip´loid) 1. having two sets of chromosomes, as normally found in the somatic cells; in humans, the diploid number is 46. 2. an individual or cell having two full sets of homologous chromosomes. number is 36. There were differences between the two species in karyotype according to according to prep. 1. As stated or indicated by; on the authority of: according to historians. 2. In keeping with: according to instructions. 3. centromere centromere Structure in a chromosome that holds together the two chromatids. It is the point of attachment to the structure that pulls the chromatids to opposite ends of the cell during cell division (see mitosis). position classification. H. fulgens karyotype was composed by 10 pairs of metacentric metacentric /meta·cen·tric/ (-sen´trik) having the centromere near the middle, so that the arms of the replicating chromosome are approximately equal in length. met·a·cen·tric adj. , 3 pairs of metacentric-submetacentric, 4 pairs of submetacentric, and 1 pair of submetacentric-subtelocentric chromosomes Chromosomes Spaghetti-like structures located within the nucleus (or central portion) of each cell. Chromosomes contain the genetic information necessary to direct the development and functioning of all cells and systems in the body. , and H. rufescens karyotypes by 8 pairs of metacentric, 6 pairs of metacentric-submetacentric, 3 pairs of submetacentric, and 1 pair of submetacentric-subtelocentric chromosomes. The relative length of chromosomes 1 to 18 was not different between the species, but 5 of their chromosomes (numbers 4, 7, 9, 11, & 18) were significantly different in relative lengths of short and long arm and in centromeric cen·tro·mere n. The most condensed and constricted region of a chromosome, to which the spindle fiber is attached during mitosis. cen index, differences that can be explained by pericentric inversions. These observed differences in karyotype between the two species support the previous contention of evolutionary divergence divergence In mathematics, a differential operator applied to a three-dimensional vector-valued function. The result is a function that describes a rate of change. The divergence of a vector v is given by by lysine lysine (lī`sēn), organic compound, one of the 20 amino acids commonly found in animal proteins. Only the l-stereoisomer appears in mammalian protein. studies. The chromosome number The chromosome number is the number of chromosomes in each cell of an organism. Haplod and diploid chromosome number The haploid chromosome number is the number of chromosomes in the gamete cell of an organism. Thus, in humans (sperm and egg cells), this number is 23. of the two species evaluated was the same than that reported for other abalones distributed in the northeast Pacific (H. cracherodii) and other abalone species distributed in the west Pacific (H. discus discus /dis·cus/ (dis´kus) pl. dis´ci [L.] disk. dis·cus n. pl. dis·ci A flat circular surface; a disk. discus pl. disci [L.] 1. , H. gigantea, and H. madaka), although as between these two species, the karyotype of those previously described was also different. KEY WORDS: chromosomes, karyotype, centromeric-index, relative-length, arm-ratio, Haliotidae INTRODUCTION Abalones grouped within the genus genus, in taxonomy: see classification. genus Biological classification. It ranks below family and above species, consisting of structurally or phylogenetically (see Haliotis, Linnaeus 1758, comprise from 60 to 70 species described worldwide (Lindberg 1992). They are distributed in the northeast Pacific, northwest Pacific, tropical west Pacific or Indo-Pacific, southwest Pacific, and Mediterranean Sea Mediterranean Sea [Lat.,=in the midst of lands], the world's largest inland sea, c.965,000 sq mi (2,499,350 sq km), surrounded by Europe, Asia, and Africa. Geography The Mediterranean is c.2,400 mi (3,900 km) long with a maximum width of c. (Lindberg 1992, Lee & Vacquier 1995). Karyotypes in abalones have been studied only for few of those 60 to 70 described species. Those species include H. cracherodii, from the northeast Pacific (Minkler 1977) with a diploid chromosome number 2 n = 36; H. discus, H. discus hannai, H. gigantea, and H. madaka from the northwest Pacific (Arai et al. 1982, Nakamura 1986, Wang et al. 1988, Okumura et al. 1995 in Okumura et al. 1999, Miyaki et al. 1997, Miyaki et al. 1999, Okumura et al. 1999) with a 2 n = 36; H. varia var·i·a n. A miscellany, especially of literary works. [Latin, from neuter pl. of varius, various.] , H. planata, H. diversicolor aquatilis, H. diversicolor diversicolor, H. ovina, and H. asinina from the Indo-Pacific or tropical west Pacific (Nakamura 1985, Nakamura 1986, Arai et al. 1988, Jarayabhand et al. 1998) with a 2 n = 32; and for H. tuberculata from the Mediterranean Sea (Colombera & Tagliaferri 1983, Arai & Wilkins 1986) with a 2n = 28. The knowledge of karyotypes in abalone species could provide useful information for systematics systematics: see classification. of abalone species, and also with a tool to determine the most adequate species for hybridization hybridization /hy·brid·iza·tion/ (hi?brid-i-za´shun) 1. crossbreeding; the act or process of producing hybrids. 2. molecular hybridization 3. . Hybridization has been reported to occur among abalone species within certain geographic areas (Owen et al. 1971, Leighton & Lewis 1982, Koike et al. 1988, Hoshikawa et al. 1998), and it represents a potentially important tool for genetic improvement of abalones. In this research, we aim to define the karyotype of two abalone species distributed in the northeast Pacific, green (or blue) abalone (Haliotis fulgens) and red abalone The red abalone, Haliotis rufescens, is a large brick colored mollusk that feeds on kelp and other algae along the coast of Oregon to Baja California. Being the largest, and most common abalone in the state it is the only species of abalone still commonly harvested in (Haliotis rufescens). The karyotypes for these species have not been described, but it was previously reported that both hybridize hy·brid·ize intr. & tr.v. hy·brid·ized, hy·brid·iz·ing, hy·brid·iz·es 1. To produce or cause to produce hybrids; crossbreed. 2. (Leighton & Lewis 1982). MATERIALS AND METHODS For both species, adult abalone was induced to spawn To launch another program from the current program. The child program is spawned from the parent program. (operating system) spawn - To create a child process in a multitasking operating system. E.g. at 2 different abalone hatcheries. For red abalone, 8 cultured organisms at the commercial laboratory "BC Abalone" in Erendira, Baja California Baja California, state, Mexico Baja California (Span.: bä`hä kälēfōr`nyä), state (1990 pop. 1,660,855), 27,628 sq mi (71,576 sq km), NW Mexico, on the Baja California peninsula. Mexicali is the capital. , Mexico were used, and for green abalone 8 wild adults kept at the Laboratory of Abalone Spat Production from "Cooperativa de Buzos y Pescadores" at Isla Natividad Isla Natividad is an island in the Pacific Ocean 6 km west off Punta Eugenia, the northwestern headland of the Mexican state of Baja California Sur. 200 meters off its northwestern end lies Roca María at , with an area of 0.074 km². , BCS (1) (The British Computer Society, Swindon, Wiltshire, England, www.bcs.org) The chartered body for information technology professionals in the U.K., founded in 1957. , Mexico. They were induced to spawn, eggs fertilized fer·til·ize v. fer·til·ized, fer·til·iz·ing, fer·til·iz·es v.tr. 1. To cause the fertilization of (an ovum, for example). 2. , and the first hatching trochophore larvae were collected for this study. For both species, only spawns that produced normal and viable larvae were used to collect samples. Miyaki et al. (1997) procedures for treating larvae and making slides were used. In short, colchicine colchicine (kŏl`chəsēn'), alkaloid extracted from plants of the genus Colchicum and especially from the corms of the autumn crocus, Colchicum autumnale (see meadow saffron). (0.1%) was applied to the larvae for 2 h, applying a hypotonic hypotonic /hy·po·ton·ic/ (-ton´ik) 1. denoting decreased tone or tension. 2. denoting a solution having less osmotic pressure than one with which it is compared. shock with sodium citrate sodium citrate n. A white crystalline or granular compound, Na3C6H5O7·2H2O, used in photography and in medicine especially as an anticoagulant of blood stored for transfusion. (1%) immediately after for 40 min. Larvae were fixed in Carnoy solution, exchanging this solution 3 times every 15 min. Slides were made by placing 50 to 100 larvae on a clean slide, adding 2 drops of cooled acetic acid acetic acid (əsē`tĭk), CH3CO2H, colorless liquid that has a characteristic pungent odor, boils at 118°C;, and is miscible with water in all proportions; it is a weak organic carboxylic acid (see carboxyl group). (60%), macerating Macerating refers to softening or breaking into pieces with liquid. It can refer to a form of food preparation. Raw, dried or preserved fruit or vegetables are soaked in liquid to soften and to absorb the flavor of the liquid. with a surgical knife to obtain a cell suspension, and dropping on this cell suspension from a height of 10-15 cm Carnoy solution to expand the macerated cells on the slide. The slides were heated and allowed to dry for approximately 1 h before staining with Giemsa (10%) for 10 min. Chromosome counts were done at 100X using an Olympus BX41 microscope. A total of 59 metaphases and 60 metaphases were counted for red abalone and for green abalone respectively. Karyotypes and quantitative measurements of chromosomes for both species were done using the best 10 metaphases obtained from each abalone species. Each metaphase metaphase /meta·phase/ (met´ah-faz) the second stage of cell division (mitosis or meiosis), in which the chromosomes, each consisting of two chromatids, are arranged in the equatorial plane of the spindle prior to separation. was selected from different slides to guarantee they were derived from different larvae. Each metaphase was digitalized using a Cool SNAP-Pro (Media Cybernetics cybernetics [Gr.,=steersman], term coined by American mathematician Norbert Wiener to refer to the general analysis of control systems and communication systems in living organisms and machines. ) camera, and transferred to an image analyses program (Image-Pro Plus 4.5 Program). Measurements of short and long arms of each chromosome, and mean relative length (RL) of chromosomes were estimated according to Thiriot-Quievreux (1984), and centromeric indices (CI) and long and short arms relative lengths (LA, SA) based on Levan et al. (1964). Classification of chromosomes was done using centromeric index according to Levan et al. (1964), using conventional names (m for metacentric, sm for submetacentric, st for subtelocentric). Those chromosomes whose mean CI fell within the limit of different types of chromosomes were classified as intermediates between the 2 classes (i.e., m-sin & sm-st). The fundamental number was estimated as White (1973), assigning the value of 4 to all metacentric, submetacentric, and subtelocentric chromosomes, and a value of 2 to telocentric tel·o·cen·tric adj. Of or relating to a chromosome having the centromere in a terminal position. pairs. Chromosomes comparisons between the two species were done by means of a karyo-ideogram (Spotorno 1985), plotting the relative length of the short versus the long arm with their confidence intervals confidence interval, n a statistical device used to determine the range within which an acceptable datum would fall. Confidence intervals are usually expressed in percentages, typically 95% or 99%. (n = 10, alpha = 0.05). RESULTS From the 60 metaphases evaluated for H. fulgens, 85% had a diploid chromosome number 2 n = 36, and for the 59 metaphases in H. rufescens 61% a 2 n = 36 (Fig. 1). [FIGURE 1 OMITTED] The karyotype and a representative metaphase from which they were compared for each species are presented in Figure 2a (H. fulgens) & 2b (H. rufescens). For H. fulgens the relative length of the largest chromosome was 7.14 and that of the smallest chromosome was 4.45. For H. rufescens the relative length of the largest chromosome was 6.71 and that of the smallest chromosome was 4.48 (Table 1). The fundamental number for both species was 72. [FIGURE 2 OMITTED] Based on the karyo-idiogram, the karyotype of H. fulgens (Fig. 3) can be classified as consisting of 10 pairs of metacentric chromosomes metacentric chromosome n. A chromosome with a centrally placed centromere that divides the chromosome into two arms having approximately equal length. , 3 pairs metacentric-submetacentric, 4 pairs submetacentric, and 1 pair submetacentric-subtelocentric (tending to subtelocentric because of its confidence interval). No telocentric chromosomes telocentric chromosome having the centromere at one end of the chromosome (terminal centromere) so that the chromosome has only one arm. were observed. The karyotype of H. rufescens is different than that in H. fulgens, because it consists of 8 pairs of metacentric chromosomes, 6 pairs metacentric-submetacentric, 3 pairs submetacentric, and 1 pair submetacentric-subtelocentric. As with H. fulgens, no telocentric chromosomes were observed for H. rufescens. [FIGURE 3 OMITTED] The analysis by the karyo-ideogram comparing relative lengths of short and long arms, and an analysis of chromosomes differences in centromeric index between the two species indicated consistent significant (P < 0.05) differences in relative lengths of short and long arms and in centromeric index between 5 of the 18 chromosomes (4, 7, 9, 11, & 18). Other chromosomes differed in CI or in one or other of the arms lengths, but not in all three (Table 1, Fig. 3). DISCUSSION From the abalone species for which karyotypes have been published, the smallest diploid number has been 2 n = 28, followed by an intermediate diploid number of 2 n = 32, and the largest diploid number reported being 2 n = 36 (Table 2). The diploid number of abalone species for which chromosomal chromosomal, adj relating to chromosome, or a configuration within the cell's nucleus that contains a linear thread of DNA that conveys genetic data. chromosomal emanating from or pertaining to chromosome. studies have been done follows a pattern associated with the geographic distribution of the species (Nakamura 1986), with a 2 n = 28 seen for the Mediterranean species H. tuberculata (also named H. lamellosa), a 2 n = 32 being present among species of the Indo-Pacific or tropical west Pacific, which includes H. varia, H. planata, H. diversicolor aquatilis, H. diversicolor diversicolor, H. asinina, and H. ovina, and the largest 2 n = 36 seen for species described for the northeast and northwest Pacific, as H. madaka, H. discus, H. gigantea, H. discus hannai, and H. cracherodii (Table 2). Based on genetic studies, today it is believed that not all those described abalone species are different. For example, lysine cDNA sequence homology homology (hōmŏl`əjē), in biology, the correspondence between structures of different species that is attributable to their evolutionary descent from a common ancestor. among 27 Haliotis species has indicated that some of the described abalone species around the world are, in fact, the same species (Lee & Vacquier 1995). Species that are possibly a single one and are included in Table 2 are, for the Pacific northwest H. madaka and H. discus hannai; for the Indo-Pacific H. diversicolor supertexta and H. diversicolor aquatilis; and from the Mediterranean H. tuberculata tuberculata and H. tuberculata lamellosa (or H. lamellosa). Two additional genetic studies based on isozyme isozyme /iso·zyme/ (i´so-zim) one of the multiple forms in which an enzyme may exist in an organism or in different species, the various forms differing chemically, physically, or immunologically, but catalyzing the same reaction. analyses have also suggested that H. madaka and H. discus are the same species (Hara & Fujio 1992 in Lee & Vacquier 1995), and that H. diversicolor diversicolor is different from H. planata and H. varia (Arai et al. 1988). Differences in karyotypes seem to confirm that H. madaka, H. discus and H. discus hannai are the same species, and that H. diversicolor diversicolor is different from H. planata and H. varia (Table 2). The diploid chromosome number, 2 n = 36 of the two species evaluated in the present study, H. rufescens and H. fulgens, is in agreement with the previously reported karyotype for only one species from the northeast Pacific, H. cracherodii (Minkler 1977), and the reported association between the diploid number with geographic distribution (Nakamura 1986). In as much as the northwest Pacific (Japan) abalone species also have a diploid number of 36, our results confirm that marked differences in karyotypes do exist between northwest and northeast Pacific abalones. Northwest Pacific abalones only have metacentric and submetacentric chromosomes, whereas northeast Pacific abalones have those types and additionally have intermediates between those types, and two (Minkler 1977) telocentric pairs of chromosomes, or one submetacentric-subtelocentric in this study. The importance of defining chromosome types as intermediates between two classes comes from different conclusions reached in different studies for the same species. For example, northwest abalone species described for northwest Pacific are very homogeneous in number of metacentric and submetacentric chromosomes, with most reports indicating that there are 10 pairs of metacentric and 8 pairs of submetacentric chromosomes in H. discus (H. discus discus, H. discus hannai, and H. madaka), and H. gigantea (Arai et al. 1982, Okumura et al. 1995 in Okumura et al. 1999, Miyaki et al. 1997, Miyaki et al. 1999). However, there are also two reports (Wang et al. 1988, Okumura et al. 1999) indicating 11 pairs of metacentric and 7 pairs of submetacentric for H. discus (H. discus hannai). The differences reported for H. discus (H. discus hannai) have been attributed to three pairs of chromosomes (4, 9, and 17) that have arm ratios close to the limits of the classification between metacentric and submetacentric (Okumura et al. 1999), resulting in ambiguous classification even within which today is believed to be the same species. Contrasting the homogeneity Homogeneity The degree to which items are similar. in types of chromosomes for northwest Pacific species, the northeast Pacific species evaluated so far indicate less homology in the numbers of metacentric (m), submetacentric (sm), and subtelocentric (st) chromosomes between species (H. cracherodii with 8 m: 8 sm: 2 st, but H. fulgens with 10 m: 3 m-sm: 4 sm: 1 sm-st, and H. rufescens with 8 m: 6 m-sm: 3 sm: 1 sm-st. Lack of homology in karyotypes has also been reported for the Indo-Pacific species studied so far, which are characterized by a diploid chromosome number of 2 n = 32. However, lack of homology in karyotypes has been reported also for what is now believed (Lee & Vacquier 1995) to be the same species (Table 2). This result can be explained by the reduced sample size used for karyotyping Karyotyping A laboratory test used to study an individual's chromosome make-up. Chromosomes are separated from cells, stained, and arranged in order from largest to smallest so that their number and structure can be studied under a microscope. , or by using low quality metaphases. For example, within this group of Indo-Pacific abalone species, two conflicting karyotypes have been reported within two species, H. varia (Nakamura 1986, Arai et al. 1988, Jarayabhand et al. 1998) and H. diversicolor (Nakamura 1985, Arai et al. 1988). Nakamura (1986) states that his data for H. varia are not precise because of the small size (1.41 to 3.63 [micro]m) of some of the chromosomes he found, and Jarayabhand et al. (1998) attributes the difference in his study with that in Arai et al. (1988) to different methodological conditions. However, the microphotographs of H. varia karyotype included in Jarayabhand et al. (1998) indicate a possible problem with measurements because of the small chromosome size and a low definition of metaphases. The differences reported for karyotypes within H. diversicolor can be explained by one author classifying 2 chromosomes as submetacentric, whereas the other one classifies those chromosomes as submetacentric-subtelocentric, indicating that the centromeric index is in the limits of both classes, pointing again to the need for more detailed classification when the chromosome centromeric indices are in, or close to the limits of two classifications. Based on the results obtained in this study, indicating that whereas the chromosomes of H. rufescens and H. fulgens do not differ in their relative length (RL), that 5 of the 18 chromosomes were different in centromeric index (CI), relative length of short arm, and relative length of long arm, it is possible to propose causes for the differences in chromosome structure between these two species. For all of those chromosomes that were different (4, 7, 9, 11, and 18), pericentric inversions can be proposed to be the evolutionary force differentiating the two species. Pericentric inversions represent a structural chromosome change known to be the most frequent mutations in the evolution of karyotypes (White 1978). Finally, another important difference between the karyotypes of the two species is the position of the only submetacentric-subtelocentric chromosome in each, based on decreasing RLs, which is in position on chromosome number 14 for H. fulgens and position on chromosome number 18 for H. rufescens, suggests a possible translocation translocation /trans·lo·ca·tion/ (trans?lo-ka´shun) the attachment of a fragment of one chromosome to a nonhomologous chromosome. Abbreviated t. event in the common linage lin·age also line·age n. 1. The number of lines of printed or written material. 2. Payment for written work at a specified amount per line. linage Noun 1. of these species. A characteristic among abalone species reported in the literature is the presumable pre·sum·a·ble adj. That can be presumed or taken for granted; reasonable as a supposition: presumable causes of the disaster. existence of hybrids. The occurrence of hybridization has been inferred from morphologic mor·phol·o·gy n. pl. mor·phol·o·gies 1. a. The branch of biology that deals with the form and structure of organisms without consideration of function. b. characteristics in natural populations (Owen et al. 1971) or from mating experiments in the laboratory (Leighton & Lewis 1982, Koike et al. 1988, Hoshikawa et al. 1998). However, genetic confirmation of hybridization has only been done for hybrids of H. kamtschatkana and H. discus hannai (Hoshikawa et al. 1998). Given the karyotype differences observed in this study it is possible to conclude that even if fertilization fertilization, in biology, process in the reproduction of both plants and animals, involving the union of two unlike sex cells (gametes), the sperm and the ovum, followed by the joining of their nuclei. between these two species can be achieved producing hybrids, those hybrids would be expected to have a reduced fertility because of improper synapses of not perfectly homologous chromosomes homologous chromosome n. Either member of a single pair of chromosomes. during meiosis (Freeman & Herron 2001). In agreement, Leighton & Lewis (1982) found a low viability (0.1%) to postlarva when mating (presumed, not genetically certified) hybrids of red and green abalone.
TABLE 1.
Karyotype comparison of Haliotis fulgeus (H.f.) and Haliotis rufescens
(H.r.): relative length RL, short arm length SA, long arm length LA,
centromeric index CI, and chromosome classification derived from 10
metaphases for each species. Standard deviations are presented
([+ or -] sd) for each mean.
RL [+ or -] sd
Chrom
pair H.f H.r.
1 7.14 [+ or -] 0.38 (a) 6.71 [+ or -] 0.51 (a)
2 6.77 [+ or -] 0.59 (a) 6.68 [+ or -] 0.31 (a)
3 6.70 [+ or -] 0.34 (a) 6.63 [+ or -] 0.40 (a)
* 4 6.55 [+ or -] 0.33 (a) 6.23 [+ or -] 0.66 (a)
5 6.43 [+ or -] 0.53 (a) 6.09 [+ or -] 0.45 (a)
6 6.05 [+ or -] 0.28 (a) 6.08 [+ or -] 0.45 (a)
* 7 5.79 [+ or -] 0.46 (a) 5.93 [+ or -] 0.22 (a)
8 5.70 [+ or -] 0.55 (a) 5.88 [+ or -] 0.45 (a)
* 9 5.55 [+ or -] 0.26 (a) 5.64 [+ or -] 0.25 (a)
10 5.27 [+ or -] 0.26 (a) 5.42 [+ or -] 0.24 (a)
* 11 5.22 [+ or -] 0.35 (a) 5.15 [+ or -] 0.33 (a)
12 5.19 [+ or -] 0.28 (a) 5.13 [+ or -] 0.24 (a)
13 4.80 [+ or -] 0.19 (a) 5.09 [+ or -] 0.25 (a)
14 4.68 [+ or -] 0.25 (a) 5.06 [+ or -] 0.18 (a)
15 4.64 [+ or -] 0.28 (a) 4.61 [+ or -] 0.20 (a)
16 4.55 [+ or -] 0.35 (a) 4.60 [+ or -] 0.22 (a)
17 4.53 [+ or -] 0.25 (a) 4.59 [+ or -] 0.26 (a)
* 18 4.45 [+ or -] 0.27 (a) 4.48 [+ or -] 0.15 (a)
SA [+ or -] sd
Chrom
pair H.f. H.r.
1 2.97 [+ or -] 0.13 (a) 3.18 [+ or -] 0.22 (a)
2 2.53 [+ or -] 0.29 (a) 2.88 [+ or -] 0.17 (a)
3 3.11 [+ or -] 0.19 (a) 3.02 [+ or -] 0.23 (a)
* 4 1.96 [+ or -] 0.16 (a) 2.44 [+ or -] 0.20 (a)
5 2.88 [+ or -] 0.25 (a) 2.07 [+ or -] 0.16 (b)
6 1.91 [+ or -] 0.18 (a) 2.26 [+ or -] 0.23 (a)
* 7 2.22 [+ or -] 0.17 (a) 1.81 [+ or -] 0.18 (b)
8 2.06 [+ or -] 0.24 (a) 2.52 [+ or -] 0.21 (b)
* 9 2.64 [+ or -] 0.17 (a) 2.18 [+ or -] 0.18 (b)
10 1.73 [+ or -] 0.10 (a) 2.26 [+ or -] 0.11 (b)
* 11 2.11 [+ or -] 0.14 (a) 2.47 [+ or -] 0.13 (b)
12 2.27 [+ or -] 0.15 (a) 1.98 [+ or -] 0.09 (b)
13 1.96 [+ or -] 0.13 (a) 2.24 [+ or -] 0.12 (b)
14 1.26 [+ or -] 0.13 (a) 1.74 [+ or -] 0.05 (b)
15 1.69 [+ or -] 0.10 (a) 1.66 [+ or -] 0.11 (a)
16 2.12 [+ or -] 0.21 (a) 1.90 [+ or -] 0.10 (a)
17 2.18 [+ or -] 0.12 (a) 2.11 [+ or -] 0.13 (a)
* 18 1.85 [+ or -] 0.13 (a) 1.13 [+ or -] 0.07 (b)
LA [+ or -] sd
Chrom
pair H.f H.r.
1 4.17 [+ or -] 0.32 (a) 3.53 [+ or -] 0.33 (a)
2 4.24 [+ or -] 0.38 (a) 3.80 [+ or -] 0.19 (a)
3 3.59 [+ or -] 0.19 (a) 3.61 [+ or -] 0.19 (a)
* 4 4.59 [+ or -] 0.32 (a) 3.79 [+ or -] 0.52 (b)
5 3.55 [+ or -] 0.31 (a) 4.02 [+ or -] 0.39 (a)
6 4.13 [+ or -] 0.16 (a) 3.83 [+ or -] 0.27 (a)
* 7 3.57 [+ or -] 0.32 (a) 4.11 [+ or -] 0.20 (b)
8 3.64 [+ or -] 0.36 (a) 3.36 [+ or -] 0.38 (a)
* 9 2.91 [+ or -] 0.14 (a) 3.46 [+ or -] 0.11 (b)
10 3.55 [+ or -] 0.19 (a) 3.16 [+ or -] 0.22 (a)
* 11 3.12 [+ or -] 0.25 (a) 2.68 [+ or -] 0.21 (b)
12 2.92 [+ or -] 0.16 (a) 3.15 [+ or -] 0.17 (a)
13 2.84 [+ or -] 0.14 (a) 2.85 [+ or -] 0.19 (a)
14 3.42 [+ or -] 0.18 (a) 3.32 [+ or -] 0.17 (a)
15 2.95 [+ or -] 0.22 (a) 2.95 [+ or -] 0.13 (a)
16 2.43 [+ or -] 0.15 (a) 2.70 [+ or -] 0.16 (a)
17 2.35 [+ or -] 0.16 (a) 2.48 [+ or -] 0.15 (a)
* 18 2.59 [+ or -] 0.18 (a) 3.35 [+ or -] 0.14 (b)
IC [+ or -] sd
Chrom
pair H.f H.r.
1 41.70 [+ or -] 1.85 (a) 47.40 [+ or -] 1.44 (b)
2 37.32 [+ or -] 2.44 (a) 43.10 [+ or -] 1.36 (b)
3 46.38 [+ or -] 1.41 (a) 45.55 [+ or -] 1.29 (a)
* 4 29.92 [+ or -] 2.29 (a) 39.33 [+ or -] 2.72 (b)
5 44.83 [+ or -] 1.39 (a) 34.10 [+ or -] 2.43 (b)
6 31.59 [+ or -] 1.78 (a) 37.07 [+ or -] 1.71 (b)
* 7 38.40 [+ or -] 1.41 (a) 30.54 [+ or -] 2.64 (b)
8 36.07 [+ or -] 2.05 (a) 42.97 [+ or -] 3.17 (b)
* 9 47.63 [+ or -] 1.52 (a) 38.66 [+ or -] 1.63 (b)
10 32.76 [+ or -] 1.14 (a) 41.80 [+ or -] 2.13 (b)
* 11 40.37 [+ or -] 1.75 (a) 48.03 [+ or -] 0.87 (b)
12 43.79 [+ or -] 1.33 (a) 38.62 [+ or -] 1.05 (b)
13 40.80 [+ or -] 1.95 (a) 43.96 [+ or -] 1.91 (a)
14 26.86 [+ or -] 1.95 (a) 34.45 [+ or -] 1.26 (b)
15 36.45 [+ or -] 1.64 (a) 36.07 [+ or -] 1.42 (b)
16 46.58 [+ or -] 1.46 (a) 41.37 [+ or -] 1.42 (b)
17 48.07 [+ or -] 1.34 (a) 46.0 [+ or -] 1.38 (a)
* 18 41.67 [+ or -] 1.59 (a) 25.14 [+ or -] 1.32 (b)
C
Chrom
pair H.f. H.r.
1 m m
2 m-sm m
3 m m
* 4 sm m-sm
5 m sm
6 sm sm-m
* 7 m-sm sm
8 sm m
* 9 m m-sm
10 sm m
* 11 m m
12 m m-sm
13 m m
14 sm-st sm
15 sm-m sm-m
16 m m
17 m m
* 18 m sm-st
* indicates that the chromosomes between the two species are different
in SA, LA, and IC. Different letters between species indicate
significant differences based on confidence intervals (P < 0.05). m,
metacentric; sm, submetacentric; st, subtelocentric.
TABLE 2.
World abalone species evaluated for their karyotype.
Distribution Species s n 2n FN m
European-Mediterranean (1)
H. tuberculata 28 56 8
" 14 28
H. Lamellosa 14 28 *
Indo-Pacific (2)
H. varia 16 32 64 * 13
" 32 64 * 9
" 32 64 * 8
H. planata 32 64 * 9
H. diversicolor 16 32 64 * 8
aquatilis
H. diversicolor 32 64 * 8
diversicolor
H. asinina 32 64 * 10
H. ovina 32 62 * 9
Pacific Northwest (3)
H. discus 36 72 * 10
" 36 72 10
" 36 72 10
H. discus 36 72 * 10
hannai
" 36 72 11
" 36 72 * 10
" 36 72 * 11
H. madaka 36 72 10
H. gigantea 18 36 *
36 72 10
Pacific Northeast (3)
H. cracherodii 36 72 * 8
H. fulgens 36 72 10
H. refuscens 36 72 8
Distribution Species m-sm sm sm-st st t
European-Mediterranean (1)
H. tuberculata 6
"
H. Lamellosa
Indo-Pacific (2)
H. varia 3
" 6 1
" 8
H. planata 6 1
H. diversicolor 5 2 1
aquatilis
H. diversicolor 7 1
diversicolor
H. asinina 6
H. ovina 6 1
Pacific Northwest (3)
H. discus 8
" 8
" 8
H. discus 8
hannai
" 7
" 8
" 7
H. madaka 8
H. gigantea
8
Pacific Northeast (3)
H. cracherodii 8 2
H. fulgens 3 4 1
H. refuscens 6 3 1
Distribution Species R[L.- C[L.- A[R.-
sup.L] sup.L] sup.L]
European-Mediterranean (1)
H. tuberculata
"
H. Lamellosa
Indo-Pacific (2)
H. varia
"
"
H. planata
H. diversicolor
aquatilis
H. diversicolor
diversicolor
H. asinina
H. ovina
Pacific Northwest (3)
H. discus
"
"
H. discus
hannai
" 7.09
"
" 6.88 1.21
H. madaka
H. gigantea
Pacific Northeast (3)
H. cracherodii
H. fulgens 7.14 41.70 1.40
H. refuscens 6.71 47.40 1.11
Distribution Species R[L.- C[I.- A[R.-
sup.S] sup.S] sup.S]
European-Mediterranean (1)
H. tuberculata
"
H. Lamellosa
Indo-Pacific (2)
H. varia
"
"
H. planata
H. diversicolor
aquatilis
H. diversicolor
diversicolor
H. asinina
H. ovina
Pacific Northwest (3)
H. discus
"
"
H. discus
hannai
" 4.11
"
" 4.64 1.10
H. madaka
H. gigantea
Pacific Northeast (3)
H. cracherodii
H. fulgens 4.45 41.67 1.41
H. refuscens 4.48 25.14 3.01
Distribution Species
Reference
European-Mediterranean (1)
H. tuberculata Arai & Wilkins 1986
" Colombera & Tagliaferri
1983
H. Lamellosa
Indo-Pacific (2)
H. varia Nakamura 1986
" Arai et al. 1988
" Jarayabhand et al. 1998
H. planata Arai et al. 1988
H. diversicolor Nakamura 1985
aquatilis
H. diversicolor Arai et al. 1988
diversicolor
H. asinina Jarayabhand et al. 1998
H. ovina Jarayabhand et al. 1998
Pacific Northwest (3)
H. discus Arai et al. 1982
" Miyaki et al. 1997
" Miyaki et al. 1997
H. discus Arai et al. 1982
hannai
" Wang et al. 1988
" Okumura et al. 1995
in Okumura et al. 1999
" Okumura et al. 1999
H. madaka Miyaki et al. 1999
H. gigantea Nakamura 1986
Miyaki et al. 1997
Pacific Northeast (3)
H. cracherodii Minkler 1977
H. fulgens Present study
H. refuscens Present study
(1) Eurotis, (2) Padollus, (3) Nordotis: subgenera subdivision
within the Haliotidae (Lee & Vacquier 1995).
FN fundamental number, m metacentric, sm submetacentric,
st subteloceniric, t telocentric, RL relative length,
CI centrometric index, AR arm ratio, [sup.L] largest
chromosome, s smallest chromosome.
* data inferred (for FN: m, sm, st = 4, and for t = 2).
(S) indicates within the same block species which have been
later found to be the same one.
ACKNOWLEDGMENTS The authors thank the abalone laboratories BC Abalone, Erendira and Cooperativa de Buzos y Pescadores Isla, Natividad for the donation of biological material, and also Susana Avila from CIBNOR for laboratory technical support. The authors also thank Dr. Nick Elliot (CSIRO CSIRO Commonwealth Scientific & Industrial Research Organization (Australia) ) and anonymous reviewers for valuable comments on the manuscript. This research was supported by CONACYT CONACYT Consejo Nacional de Ciencia y Tecnología (National Board of Science and Technology; Mexico, Bolivia, Paraguay) grant 38860-B to A. M. Ibarra. LITERATURE CITED Arai, K., K. Fujino & M. Kudo ku·do n. pl. ku·dos Usage Problem A praising remark; an accolade or compliment: "Children's book author Virginia Hamilton added another kudo to her prize-laden career" . 1988. Karyotype and zymogram zy·mo·gram n. A strip or band of electrophoretic medium showing the pattern of enzymes or isoenzymes after their separation by electrophoresis. differences among three species of the abalones Haliotis planata, H. varia, and H. diversicolor diversicolor. Nippon Suisan Gakkaishi 54:2055-2064. Arai, K., H. Tsubaki, Y. Ishitani & K. Fujino. 1982. Chromosomes of Haliotis discus hannai Ino and Haliotis discus Reeve REEVE. The name of an ancient English officer of justice, inferior in rank to an alderman. 2. He was a ministerial officer, appointed to execute process, keep the king's peace, and put the laws in execution. . Bull. Japan. Soc. Sci. Fish. 48:1689-1691. Arai, K. & N. P. Wilkins. 1986. Chromosomes of Haliotis tuberculata L. Aquaculture aquaculture, the raising and harvesting of fresh- and saltwater plants and animals. The most economically important form of aquaculture is fish farming, an industry that accounts for an ever increasing share of world fisheries production. 58:305-308. Colombera, D. & F. Tagliaferri. 1983. Chromosomes from male gonads of Haliotis tubercolata and Haliotis lamellosa (Haliotidae, Archeogasteropoda, Mollusca). Caryologia 36:231-234. Freeman, S. & J. C. Herron. 2001. Evolutionary analysis. Upper Saddle River Saddle River may refer to:
In 1913, law professor Dr. . pp. 90-91. Hara, M., Y. Fujio. 1992. Genetic relationships among abalone species. Suisan Ikushu. Mar. Aquacult. 17:55-61 (in Japanese). Hoshikawa, H., Y. Sakai & A. Kijima. 1998. Growth characteristics of the hybrid between pinto pinto Spotted horse, also called paint, piebald, skewbald, and other terms to describe variations in colour and markings. The American Indian ponies of the western U.S. were often pintos. Most pure-breed associations refuse to register horses with pinto colouring. abalone, Haliotis kamtschatkana Jonas, and ezo abalone, H. discus hannai Ino, under high and low temperatures. J. Shellfish shellfish, popular name for certain edible mollusks (see Mollusca), e.g., oysters, clams, and scallops, and for certain edible crustaceans, e.g., crabs, lobsters, and shrimps. All are aquatic invertebrates with shells; they are not fish. Res. 17:673-677. Jarayabhand, P., R. Yom-La & A. Popongviwat. 1998. Karyotypes of marine molluscs in the family Haliotidae Noun 1. family Haliotidae - abalones Haliotidae mollusk family - a family of mollusks class Gasteropoda, class Gastropoda, Gasteropoda, Gastropoda - snails and slugs and their relatives found in Thailand. J. Shellfish Res. 17:761-764. Koike, Y., Z. Sun & F. Takashima. 1988. On the feeding and growth of juvenile hybrid abalones. Suisanzoshoku 36:231-235. Lee, Y.-H. & V. D. Vacquier. 1995. Evolution and systematics in Haliotidae (Mollusca: Gastropoda): inferences from DNA sequences DNA sequence Genetics The precise order of bases–A,T,G,C–in a segment of DNA, gene, chromosome, or an entire genome. See Base pair, Base sequence analysis, Chromosome, Gene, Genome. of sperm lysin Lysin A term used to describe substances that will disrupt a cell, with the release of some of its constituents. Unless the damage is minor, this action leads to the death of the cell. . Mar. Biol. 124:267-278. Leighton, D. L. & C. A. Lewis. 1982. Experimental hybridization in abalones. Int. J. Invert in·vert v. 1. To turn inside out or upside down. 2. To reverse the position, order, or condition of. 3. To subject to inversion. n. Something inverted. . Reprod. 5:273-282. Levan, A., K. Fredga & A. Sandberg. 1964. Nomenclature nomenclature /no·men·cla·ture/ (no´men-kla?cher) a classified system of names, as of anatomical structures, organisms, etc. binomial nomenclature for centromeric position on chromosomes. Hereditas 52:201-220. Lindberg, D. R. 1992. Evolution, distribution and systematics of Haliotidae. In: S. A. Shepherd, M. J. Tegner & S. A. Guzman del Proo, editors. Abalone of the world. Biology, fisheries fisheries. From earliest times and in practically all countries, fisheries have been of industrial and commercial importance. In the large N Atlantic fishing grounds off Newfoundland and Labrador, for example, European and North American fishing fleets have long and culture, 1st ed. Cambridge: Fishing News Books. pp. 3-18. Minkler, J. 1977. Chromosomes of the black abalone Miyaki, K., M. Matsuda & O. Tabeta. 1999. Karyotype of the giant abalone, Nordotis madaka. Fisheries Sci. 65:317-318. Miyaki, K., O. Tabeta & H. Kayano. 1997. Karyotypes of the two species of abalones Nordotis discus and N. gigantea. Fisheries Sci. 63:179-180. Nakamura, H. K. 1985. The chromosomes of Haliotis diversicolor aquatilis (Archaeogastropoda: Haliotidae). Mal. Rev. 18:113-114. Nakamura, H. K. 1986. Chromosomes of Archaeogastropoda (Mollusca: Prosobranchia), with some remarks on their cytotaxonomy cy·to·tax·on·o·my n. The classification of organisms based on cellular structure and function, especially on the structure and number of chromosomes. cy and phylogeny. Publ. Seto. Mar. Biol. Lab. 31:191-267. Okumura, S., S. Kinugawa, A. Fujimaki, W. Kawai, H. Maehata, K. Yoshioka, R. Yoneda & K. Yamamori. 1999. Analysis of karyotype, chromosome banding chromosome band n. An area across the width of a chromosome that stains darkly or in a contrasting manner. , and nucleolus organizer region Nucleolus organizer region (NOR) is a chromosomal region around which the nucleolus forms. It is also called the "nucleolar organizer". The region contains several tandem copies of ribosomal RNA genes. See also
Okumura, S., S. Yamada, T. Sugie, D. Sekimiya, A. Toda, H. Hajime, H. Hatano & K. Yamamori. 1995. C-banding Study of chromosomes in Pacific abalone Haliotis discus hannai (Archaeogastropoda: Haliotidae) Chrom Inf. Ser. 18:605-609. Owen, B., J. H. McLean & R. J. Meyer. 1971. Hybridization in the eastern pacific abalones (Haliotis). Sci. Bull. Nat. Hist. Mus. Los Ang. Cty. 9:1-37. Spotorno, A. E. 1985. Conceptos y metodos en cariologia descriptiva y comparada. In: R. Fernandez-Donoso, editor. El nucleo, los cromosomas y la evolucion. UNESCO UNESCO: see United Nations Educational, Scientific, and Cultural Organization. UNESCO in full United Nations Educational, Scientific and Cultural Organization , pp. 137-165. Thiriot-Quievreux, C. 1984. Analyse comparee des caryotypes d'Ostreidae (Bivalvia). Cah. Biol. Mar. 25:407-418. Wang, Q., Q. Ma & Y. Wang. 1988. The karyotype study of Haliotisdiscus-hannai Ino. Zool. Res. 9:171-174. White, M. J. D. 1973. Animal cytology cytology (sītŏl`əjē), in biology, the study of the structure of all normal and abnormal components of cells and the changes, movements, and transformations of such components. and evolution. Cambridge: Cambridge University Press Cambridge University Press (known colloquially as CUP) is a publisher given a Royal Charter by Henry VIII in 1534, and one of the two privileged presses (the other being Oxford University Press). , 3rd. ed Rd. abbr. road . 961 pp. White, M. J. D. 1978. Modes of Speciation speciation Formation of new and distinct species, whereby a single evolutionary line splits into two or more genetically independent ones. One of the fundamental processes of evolution, speciation may occur in many ways. . San Fracisco CA: W. H. Freeman. 455 pp. NORMA Norma priestess betrays her vows and sacrifices herself in atonement. [Ital. Opera: Bellini Norma in Benét, 720] See : Sacrifice K. HERNANDEZ-IBARRA, (1) CARLOS MARQUEZ, (2) JOSE L. RAMIREZ (1) AND ANA M. IBARRA (1) * * Corresponding author: E-mail aibarra@cibnor.mx (1) Centro de Investigaciones Biologicas del Noroeste, S.C., Lab. de Genetica Acuicola A.P. 128. La Paz La Paz, city, Bolivia La Paz (lä päs), city (1992 pop. 713,378), W Bolivia, administrative capital (since 1898) and largest city of Bolivia. The legal capital is Sucre. B.C.S., Mexico 23000; (2) Universidad Autonoma de Baja California, Facultad de Ciencias. Carr. Tijuana, Ensenada Km. 106, Ensenada B.C., Mexico 22800 |
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