共查询到20条相似文献,搜索用时 15 毫秒
1.
Levin DA Palestis BG Jones RN Trivers R 《Evolution; international journal of organic evolution》2005,59(5):962-969
We determined whether supernumerary B chromosomes were nonrandomly distributed among major angiosperm lineages and among lineages within families, as well as the identity of lineages with unusually high B-chromosome frequencies (hot spots). The incidence of B chromosomes for each taxon was gathered from databases showing species with and without these chromosomes (among species with known chromosome numbers). Heterogeneity was found at all ranks above the species level. About 8% of monocots had B chromosomes versus 3% for eudicots; they were rare in nonmonocot basal angiosperms. Significant heterogeneity in B-chromosome frequency occurred among related orders, families within orders, and major taxa within families. There were many B-chromosome hot spots, including Liliales and Commelinales at the order level. At the family level, there was a trend suggesting that B-chromosome frequencies are positively correlated with genome size. 相似文献
2.
In a survey of epigean and cave streams in the São Domingos karst area, 38 species were present in the stream reaches, including 10 characiforms, 19 siluriforms, seven gymnotiforms and two perciforms. One species of Astyanax and the new armoured catfish species Parotocinclus were the most common epigean fishes in São Domingos. The most conspicuous non-troglomorphic cave fishes were Hoplerythrinus unitaeniatus , Astyanax sp., Brycon sp. and two species of Imparfinis , with I. hollandi being the most common fish in most caves. São Domingos karst area has the most diverse and abundant Brazilian cavefish fauna, not only in terms of troglobitic species but also in general fish richness, with 22 non-troglomorphic species recorded in caves in addition to five troglobitic ones. Most fishes examined for stomach contents had at least partially full stomachs. The studied fishes were carnivorous, feeding primarily on aquatic insects. Fishes with developed gonads recorded in caves were I. hollandi , Rhamdia quelen , Pseudocetopsis plumbeus , Hoplerythrinus unitaeniatus and Cichlasoma araguaiensis , indicating a potential for reproduction in the subterranean habitat. 相似文献
3.
In this study, patterns of spatial synchrony in population fluctuations (cross-correlation) of an endemic fish assemblage of a Neotropical reservoir (Segredo Reservoir, Igua?u River, Paraná State, Brazil) were reported. First, the level of population synchrony for 20 species was estimated. Second, population synchrony was correlated, using the Mantel test, with geographical distances among sites (n = 11) and also environmental synchrony (temperature). Nine species presented significant correlations between spatial synchrony and geographic distances (Astyanax sp. b, Astyanax sp. c, Pimelodus sp., Hoplias malabaricus, Crenicichla iguassuensis, Hypostomus derbyi, Hypostomus myersi, Rhamdia branneri, and R. voulezi). Considering the ecology of the species and the significant relationship between population and environmental synchronies, it seems that environmental stochasticity is the most plausible hypothesis in explaining the observed synchrony patterns. 相似文献
4.
5.
Dispensable, supernumerary (B) chromosomes are found in diverse eukaryotic species. The origin and genetic consequences of B chromosomes have been the subjects of speculation for more than a century. Until now, there has been no molecular evidence that B chromosome DNA is transcribed and there is no unequivocal evidence as to their origin. B chromosomes are considered to be genetically inert although they appear to cause a variety of phenotypic effects. We report that members of one of two ribosomal RNA gene families that are confined to the B chromosomes of a plant, Crepis capillaris, are transcribed--thus providing the first molecular evidence of gene activity on B chromosomes. Sequence analysis of part of the A and B chromosome rRNA genes, together with comparisons with related species, indicates that the B chromosome rRNA genes originate from the A chromosome. 相似文献
6.
Rafael Splendore de Borba Edson Louren?o da Silva Ana Carolina Sales Pacheco Patricia Pasquali Parise-Maltempi Anderson Luis Alves 《Reviews in Fish Biology and Fisheries》2012,22(2):509-518
The Heptapteridae family is endemic to the Neotropics and is one of the most representative members of the Siluriformes order
in small bodies of water. Due the lack of data for clearly distinguishing their species, only recently was elevated from condition
of subfamily to family. However, many doubts about certain species remain yet. There are a relatively large number of cytogenetics
studies about heptapterids that permits comparative analyses focused in the karyotype evolution of the group. However, the
absence of studies about this theme motivated this work. Were analyzed cytogenetically most representative species of the
family: Rhamdia, Imparfinis, Pimelodella, Phenacorhamdia, and Taunaya, and compared with available data from the family. The comparative analysis indicated the predominance of biarmed chromosomes
and low variation of the diploid number (around 2n = 58) suggesting that centric inversions were more important than centric
fissions in the history of heptapterids. It is corroborated by a remarkable number of NOR phenotypes mainly in Imparfinis and Rhamdia species. A probable condition of Heptapteridae plesiomorphic karyotype would be one composed of 2n = 58 chromosomes of types
metacentric and submetacentric mainly, with simple NOR at the sub terminal position. The reduction of diploid number, it would
possibly through successive events of chromosome fusion with deletions and inversion rearrangements responsible for NOR variation
within the certain genus. The occurrence of B chromosomes is from a derived event, possibly of recent origin, without phylogenetic
implications. 相似文献
7.
Prochilodus lineatus, an abundant species in the Mogi-Guaçu river basin, represents a large part of the region's fishing potential. Karyotypic analyses based on classic cytogenetic techniques have revealed the presence of 54 meta-submetacentric type chromosomes, together with the occurrence of small supernumerary chromosomes with intra and interindividual variations. This paper describes the genomic organization of two families of satellite DNA in the P. lineatus genome. The chromosomal localization these two repetitive DNA families through fluorescence in situ hybridization (FISH) demonstrated that the SATH1 satellite DNA family, composed of approximately 900 bp, was located in the pericentromeric region of a group of chromosomes of the standard complement, as well as on all the B chromosomes. The SATH2 satellite family has a monomeric unit of 441 bp and was located in the pericentromeric regions of some chromosomes of the standard complement, but was absent in the B chromosomes. Double FISH analyses showed that these two families participate jointly in the pericentromeric organization of several chromosomes of this species. The data obtained in this study support the hypothesis that the B chromosomes derive from chromosomes of the standard complement, which are carriers of the SATH1 satellite DNA. 相似文献
8.
The taxonomy of trematodes of Great Barrier Reef (GBR) fishes has been studied in some detail for over 20 years. Understanding of the fauna has been informed iteratively by approaches to sampling, understanding of morphology, the advent of molecular methodology and a feed-back loop from the emergent understanding of host specificity. Here we analyse 658 host-parasite combinations for 290 trematode species, 152 genera and 28 families from GBR fishes. These are reported from 8 orders, 38 families, 117 genera and 243 species of fishes. Of the 290 species, only 4 (1·4%) have been reported from more than one order of fishes and just 23 (7·9%) infect more than one family; 77·9% of species are known from only one genus, and 60% from only one species of fish. Molecular studies have revealed several complexes of cryptic species and others are suspected; we conclude that no euryxenous host distribution should be accepted on the basis of morphology only. The occurrence of individual trematode species in potential hosts is patchy and difficult to predict reliably a priori or explain convincingly a posteriori. These observations point to the need for a vigorous iterative interaction between the accretion of host specificity data and its interpretation. 相似文献
9.
Bertollo LA Oliveira C Molina WF Margarido VP Fontes MS Pastori MC Falcão Jd Fenocchio AS 《Heredity》2004,93(2):228-233
The genus Erythrinus belongs to the family Erythrinidae, a neotropical fish group. This genus contains only two described species, Erythrinus erythrinus being the most widely distributed in South America. Six samples of this species from five distinct Brazilian localities and one from Argentina were studied cytogenetically. Four groups were identified on the basis of their chromosomal features. Group A comprises three samples, all with 2n = 54 chromosomes, a very similar karyotypic structure, and the absence of chromosome differentiation between males and females. One sample bears up to four supernumerary microchromosomes, which look like 'double minute chromosomes' in appearance. Groups B-D comprise the three remaining samples, all sharing an X(1)X(1)X(2)X(2)/X(1)X(2)Y sex chromosome system. Group B shows 2n = 54/53 chromosomes in females and males, respectively, and also shows up to three supernumerary microchromosomes. Groups C and D show 2n=52/51 chromosomes in females and males, respectively, but differ in the number of metacentric, subtelocentric, and acrocentric chromosomes. In these three groups (B-D), the Y is a metacentric chromosome clearly identified as the largest in the complement. The present results offer clear evidence that local samples of E. erythrinus retain exclusive and fixed chromosomal features, indicating that this species may represent a species complex. 相似文献
10.
Duílio Mazzoni Zerbinato de Andrade Silva Cristian Araya-Jaime Masakane Yamashita Mateus Rossetto Vidal Claudio Oliveira Fbio Porto-Foresti Roberto Ferreira Artoni Fausto Foresti 《Genetics and molecular biology》2021,44(3)
B chromosomes are non-essential additional genomic elements present in several animal and plant species. In fishes, species of the genus Psalidodon (Characiformes, Characidae) harbor great karyotype diversity, and multiple populations carry different types of non-essential B chromosomes. This study analyzed how the dispensable supernumerary B chromosome of Psalidodon paranae behaves during meiosis to overcome checkpoints and express its own meiosis-specific genes. We visualized the synaptonemal complexes of P. paranae individuals with zero, one, or two B chromosomes using immunodetection with anti-medaka SYCP3 antibody and fluorescence in situ hybridization with a (CA)15 microsatellite probe. Our results showed that B chromosomes self-pair in cells containing only one B chromosome. In cells with two identical B chromosomes, these elements remain as separate synaptonemal complexes or close self-paired elements in the nucleus territory. Overall, we reveal that B chromosomes can escape meiotic silencing of unsynapsed chromatin through a self-pairing process, allowing expression of their own genes to facilitate regular meiosis resulting in fertile individuals. This behavior, also seen in other congeneric species, might be related to their maintenance throughout the evolutionary history of Psalidodon. 相似文献
11.
Specimens belonging to two fish species genus Rhamdia were cytogenetically analysed from seven localities in Brazil and Argentina. In addition to the 58 chromosomes of the basic karyotype, one to five metacentric B chromosomes were observed carrying conspicuous heterochromatic blocks on the distal regions of both chromosome arms. These B chromosomes are mitotically stable and, in the two best-sampled populations in R. hilarii (Lobo and 29 reservoirs), they showed frequency distributions fitting a binomial distribution, though Bs were more frequent in the latter. The presence of B chromosomes with the same appearance in R. quelen suggests an ancient origin for these B chromosomes, presumably prior to speciation from a common ancestor. 相似文献
12.
Almeida-Toledo LF Ozouf-Costaz C Foresti F Bonillo C Porto-Foresti F Daniel-Silva MF 《Cytogenetic and genome research》2002,97(3-4):229-233
Major and 5S ribosomal genes have been localized in chromosomes from five fish species, genus Astyanax, using in situ hybridization (FISH) with 28S and 5S rDNA probes. In situ signals for the major rDNA co-localized with the 5S rDNA clusters in the pericentromeric region of one marker chromosome in all five species analyzed. The conserved localization of these two rDNA clusters in the five related Astyanax species was considered as indicative of a close relationship among them. The use of these molecular markers for elucidating evolutionary relationships among closely related taxa is discussed. 相似文献
13.
P. C. Venere † I. L. Souza L. K. S. Silva M. B. Dos Anjos ‡ R. R. De Oliveira ‡ P. M. Galetti Jr§ 《Journal of fish biology》2008,72(8):1976-1989
Neotropical Curimatidae fishes include 97 species in eight genera. Basic cytogenetic studies show a karyotype of 2 n = 54 chromosomes in most species. Karyotype divergence of the nucleolus organizing regions between species has been reported, and these regions appear to be good cytotaxonomic markers. In the present work, karyotype, heterochromatin and Ag-NOR variability in 13 species were investigated to analyse the chromosome diversification in view of the biogeographic history of this group. Only Cyphocharax platanus showed a karyotype with 2 n = 58 chromosomes. Ag-NOR and C-banding patterns were quite divergent among the species studied. All species whose C-bands were analysed had heterochromatic blocks associated with the nucleolus organizing regions. Species with multiple Ag-NORs also showed an increase in NOR-associated heterochromatic blocks. C-banding showed considerable differentiation among species, revealing a pronounced chromosome diversification in this group. Karyotypic variability corroborates the hypothesis that these fishes in Amazon region show various discrete patterns of species endemism. Chromosome diversification in curimatids has a recent origin and appears to be accompanying the post-Andean speciation responsible for the diversity of species in the family. 相似文献
14.
Hashimoto DT Ferguson-Smith MA Rens W Foresti F Porto-Foresti F 《Cytogenetic and genome research》2011,134(1):64-71
We report here on the physical mapping of the H1 histone genes (hisDNA) and the 5S ribosomal DNA (rDNA) in 3 Neotropical fish species of the genus Astyanax(A. altiparanae, A. bockmanni and A. fasciatus) and the comparative analysis of the chromosomes bearing these genes. Nucleotide analyses by sequencing of both genes were also performed. The distribution of the H1 histone genes was more conserved than that of the rRNA genes, since these were always located in the pericentromeric regions of 2 chromosome pairs. 5S rDNA was found on one of the pairs that presented an H1 histone cluster; this seems to be a conserved chromosomal feature of the genus Astyanax. In addition, individuals of A. bockmanni and A. fasciatus showed clusters of 5S rDNA on 1 pair of acrocentric chromosomes, not found in A. altiparanae. The results obtained by chromosome mapping as well as by sequencing of both genes showed that A.bockmanni is more closely related to A. fasciatus than to A. altiparanae. The results allow the characterization of cytogenetic markers for improved elucidation of the processes involved in karyotype differentiation of fish genomes. 相似文献
15.
Annotated checklist of the living sharks,batoids and chimaeras (Chondrichthyes) of the world,with a focus on biogeographical diversity
下载免费PDF全文
![点击此处可从《Journal of fish biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
S. Weigmann 《Journal of fish biology》2016,88(3):837-1037
An annotated checklist of the chondrichthyan fishes (sharks, batoids and chimaeras) of the world is presented. As of 7 November 2015, the number of species totals 1188, comprising 16 orders, 61 families and 199 genera. The checklist includes nine orders, 34 families, 105 genera and 509 species of sharks; six orders, 24 families, 88 genera and 630 species of batoids (skates and rays); one order, three families, six genera and 49 species of holocephalans (chimaeras). The most speciose shark orders are the Carcharhiniformes with 284 species, followed by the Squaliformes with 119. The most species‐rich batoid orders are the Rajiformes with 285 species and the Myliobatiformes with 210. This checklist represents the first global checklist of chondrichthyans to include information on maximum size, geographic and depth distributions, as well as comments on taxonomically problematic species and recent and regularly overlooked synonymizations. Furthermore, a detailed analysis of the biogeographical diversity of the species across 10 major areas of occurrence is given, including updated figures for previously published hotspots of chondrichthyan biodiversity, providing the detailed numbers of chondrichthyan species per major area, and revealing centres of distribution for several taxa 相似文献
16.
B chromosomes occur in several Neotropical fish species. Cytogenetic analysis of 27 specimens (15 females and 12 males) of Astyanax scabripinnis paranae from the Araquá river (a small headwater tributary of the Tietê river) shows that this population has 2n=50 chromosomes (4M+30 SM+4ST+12A), two chromosome pairs with NORs and conspicuous C-band positive blocks in the terminal position of the long arm of four chromosome pairs. In this population, eight females presented 2n=51 chromosomes and the extra chromosome was a large metacentric similar in size and morphology to the first chromosome pair in the karotype. This accessory chromosome is entirely heterochromatic in C-banded metaphases and shows a late replication pattern evidenced by BrdU incorporation. There was no significant correlation between the presence of B chromosomes and increased NOR activity at the P>0.05 level. Some aspects related to these B chromosomes are discussed. 相似文献
17.
B chromosomes are supernumerary genomic elements most likely derived from the standard (A) chromosomes, whose dispensability has freed their DNA sequences to evolve fast, thus making it difficult to uncover their ancestry. Here, we show the ancestry of a B chromosome in the grasshopper Eumigus monticola by means of the high-throughput analysis of the satellitome, i.e., the whole collection of satellite DNA (satDNA). The satellitome found in this species consists of 27 satDNA families, with monomer length between 5 and 325 nt and A + T content between 42.9 and 83.3 %. Two out of the 20 clustered satDNA families (EmoSat26–41 and EmoSat27–102) were observed only on the B chromosome. The A chromosome carrying the highest number of satDNA families was the megameric S8 (13 families), six of which were also present in the B chromosome, and three of these were exclusive of the S8 and B chromosomes. The absence in the B chromosome of the H3 histone gene cluster (located interstitially on S8) and three satDNA families (located distally on S8) allowed delimiting the possible origin of the B chromosome to the proximal third of the S8 autosome, through a breakpoint between EmoSat11–122 and the H3 cluster. Interestingly, bioinformatic analysis revealed the presence of seeds for the two B-specific satDNAs in the A chromosomes, suggesting their massive amplification in the B chromosome after its origin. Therefore, intraspecifically arisen B chromosomes can harbor DNA sequences apparently being B-specific. 相似文献
18.
Pierre-Olivier Antoine Rodolfo Salas-Gismondi François Pujos Morgan Ganerød Laurent Marivaux 《Journal of Mammalian Evolution》2017,24(1):5-17
A state-of-the-art review of the Cenozoic fossil record from Western Amazonia is provided, based on literature and new data (regarding Paleogene native ungulates). It allows summarizing the evolution and dynamics of middle Eocene–Holocene mammalian guilds, at the level of species, families, and orders. Major gaps in the Western Amazonian mammal record occur in the pre-Lutetian and early Miocene intervals, and in the Pliocene epoch. Twenty-three orders, 89 families, and 320 species are recognized in the fossil record, widely dominated by eutherians from the middle Eocene onward. Probable Allotheria (Gondwanatheria) occur only in the earliest interval, whereas Metatheria and Eutheria are conspicuous components of any assemblage. Taxonomic diversity was probably fairly constant at the ordinal level (~12–14 orders in each time slice considered) and much more variable in terms of family and species richness: if most intervals are characterized by 40–50 co-occurring species and 19–31 co-occurring families, the early Miocene period illustrates a depauperate fauna (21 species, 17 families), strongly contrasting with the late Miocene climactic guild (82 species, 38 families). Recent mammalian taxonomic diversity from Western Amazonia (12 orders, 37 families, and 286 species) is at odds with all past intervals, as it encompasses only three orders of South American origin (Didelphimorphia, Cingulata, and Pilosa) but four North American immigrant orders (Artiodactyla, Perissodactyla, Carnivora, and Lagomorpha). In terms of taxonomic diversity, recent mammalian guilds are fully dominated by small-sized taxa (Chiroptera, Rodentia, and Primates). This overview also confirms the scarcity of large mammalian flesh-eaters in ancient Neotropical mammalian assemblages. The pattern and the timing of mammalian dispersals from northern landmasses into Western Amazonia are not elucidated yet. 相似文献
19.
Karyotypic evolution and phylogeny of Mexican Passalidae (Coleoptera: Polyphaga: Scarabaeoidea) 总被引:1,自引:0,他引:1
J. Serrano J. Galián P. Reyes-Castillo 《Journal of Zoological Systematics and Evolutionary Research》1998,36(4):159-167
The chromosomes of 26 taxa from Mexico of the tribes Passalini (three species) and Proculini (23 species) have been studied, increasing the karyotypically known species of the family Passalidae to 56. Karyotypic dynamism is high since the diploid number varies from 18 to 44 in the tribe Proculini. and from 25 to 31 in the tribe Passalini. In addition, supernumerary chromosomes, chromosome heteromorphism, translocations and possible sex multivalents have been found. These results contrast with the numerical conservatism found in related families of the superfamily Scarabaeoidea. However, both tribes are conservative with regard to sex determination, as all species of Proculini have male XY chromosomes whereas species of the Passalini have male XO chromosomes. It is postulated that differences in patterns shown by these two tribes are mainly due to population structure, because many species of Proculini are endemic to restricted areas of Meso and South America, favouring the settlement of karyotypic changes, whereas species of Passalini are distributed over large areas in the lowlands. It is also postulated that the ancestral karyotypic formula of the family is close to 12–14 pairs of autosomes although the ancestral male sex determination may be either XY or XO. At present only a weak relationship between morphological and karyotypic evolution has been found, which together with the marked numerical variability found within and between genera make it difficult to obtain phylogenetic conclusions from karyotypic results. 相似文献
20.
E. D. Vasil’eva D. A. Medvedev Trinh Thi Lan Chi D. V. Prazdnikov D. S. Pavlov Nguyen Thi Nga V. P. Vasil’ev 《Journal of Ichthyology》2013,53(6):380-396
We performed the first large-scale study of the species structure of the fishes living in the inland water bodies of Phu Quoc Island and identified 97 species of bony fishes, which represent 41 families of 13 orders. Taking into account the results of earlier studies, we compiled a total checklist of the island’s ich-thyofauna, which includes 99 species; one more species recorded in a previous publication on the ichthyo-fauna of the island can be added to this number, as well as 15–20 mostly euryhaline species, which needed clarification of their states. Only one species on the checklist, Oreochromis niloticus, has been introduced to the island; 14 species, mostly of the family Gobiidae, have never been recorded in the faunas of other regions of Vietnam. Two new species, probably endemic to the island, have been found and described (in the genera Rasbora and Barbucca). Two more species of the order Siluriformes should probably also be described as new. 相似文献