Karyotype Evolution and Distinct Evolutionary History of the W Chromosomes in Swallows (Aves, Passeriformes)

2019 ◽  
Vol 158 (2) ◽  
pp. 98-105 ◽  
Author(s):  
Suziane A. Barcellos ◽  
Rafael Kretschmer ◽  
Marcelo S. de Souza ◽  
Alice L. Costa ◽  
Tiago M. Degrandi ◽  
...  

As in many other bird groups, data on karyotype organization and distribution of repetitive sequences are also lacking in species belonging to the family Hirundinidae. Thus, in the present study, we analyzed the karyotypes of 3 swallow species (Progne tapera, Progne chalybea, and Pygochelidon cyanoleuca) by Giemsa and AgNOR staining, C-banding, and FISH with 11 microsatellite sequences. The diploid chromosome number was 2n = 76 in all 3 species, and NORs were observed in 2 chromosome pairs each. The microsatellite distribution pattern was similar in both Progne species, whereas P. cyanoleuca presented a distinct organization. These repetitive DNA sequences were found in the centromeric, pericentromeric, and telomeric regions of the macrochromosomes, as well as in 2 interstitial blocks in the W chromosome. Most microchromosomes had mainly telomeric signals. The Z chromosome displayed 1 hybridization signal in P. tapera but none in the other species. In contrast, the W chromosome showed an accumulation of different microsatellite sequences. The swallow W chromosome is larger than that of most Passeriformes. The observed enlargement in chromosome size might be explained by these high amounts of repetitive sequences. In sum, our data highlight the significant role that microsatellite sequences may play in sex chromosome differentiation.

2015 ◽  
Vol 146 (2) ◽  
pp. 136-143 ◽  
Author(s):  
Priscilla C. Scacchetti ◽  
Ricardo Utsunomia ◽  
José C. Pansonato-Alves ◽  
Marcelo R. Vicari ◽  
Roberto F. Artoni ◽  
...  

The speciose neotropical genus Characidium has proven to be a good model for cytogenetic exploration. Representatives of this genus often have a conserved diploid chromosome number; some species exhibit a highly differentiated ZZ/ZW sex chromosome system, while others do not show any sex-related chromosome heteromorphism. In this study, chromosome painting using a W-specific probe and comparative chromosome mapping of repetitive sequences, including ribosomal clusters and 4 microsatellite motifs - (CA)15, (GA)15, (CG)15, and (TTA)10 -, were performed in 6 Characidium species, 5 of which possessed a heteromorphic ZW sex chromosome system. The W-specific probe showed hybridization signals on the W chromosome of all analyzed species, indicating homology among the W chromosomes. Remarkably, a single major rDNA-bearing chromosome pair was found in all species. The 18S rDNA localized to the sex chromosomes in C. lanei, C. timbuiense and C. pterostictum, while the major rDNA localized to one autosome pair in C. vidali and C. gomesi. In contrast, the number of 5S rDNA-bearing chromosomes varied. Notably, minor ribosomal clusters were identified in the W chromosome of C. vidali. Microsatellites were widely distributed across almost all chromosomes of the karyotypes, with a greater accumulation in the subtelomeric regions. However, clear differences in the abundance of each motif were detected in each species. In addition, the Z and W chromosomes showed the differential accumulation of distinct motifs. Our results revealed variability in the distribution of repetitive DNA sequences and their possible association with sex chromosome diversification in Characidium species.


Genome ◽  
2012 ◽  
Vol 55 (11) ◽  
pp. 735-753 ◽  
Author(s):  
K.K. Nkongolo ◽  
M. Mehes-Smith

The family Pinaceae is made up mostly of diploid species (2n = 24). Systematization of karyotype analysis was developed to make comparison of intra- and interspecific karyotypes among the Pinaceae more accurate and reliable. Considering all parameters, the genera Pseudotsuga and Pseudolarix have the “most derived” (or advanced) and asymmetric karyotypes in the Pinaceae, followed by Larix, Picea, Abies, and Cedrus. The genus Pinus was the “least derived” (or ancestral) of all the genera of the Pinaceae analyzed. Differences in karyotype formulae and asymmetry indices were found among species within the same genera, suggesting that structural changes may have contributed to the diversification of the genus. This review is a detailed analysis of comparative karyotyping based on similar parameters, including numeric data and cytogenetic information. Telomeric sequence repeats and rDNA distribution in the Pinaceae were surveyed. The role of transposition in rDNA chromosome distribution is analyzed. Cytogenetic implications of hybridization between related species are reported. Likewise, the relationships between molecular phylogenetic and karyotype evolution is discussed in light of several reports. Within many genera, chromosomal organization was conserved despite independent molecular divergence and adaptation through the evolutionary history of the species of the Pinaceae.


Genetics ◽  
2003 ◽  
Vol 164 (1) ◽  
pp. 259-268
Author(s):  
Hannah Sundström ◽  
Matthew T Webster ◽  
Hans Ellegren

Abstract The rate of mutation for nucleotide substitution is generally higher among males than among females, likely owing to the larger number of DNA replications in spermatogenesis than in oogenesis. For insertion and deletion (indel) mutations, data from a few human genetic disease loci indicate that the two sexes may mutate at similar rates, possibly because such mutations arise in connection with meiotic crossing over. To address origin- and sex-specific rates of indel mutation we have conducted the first large-scale molecular evolutionary analysis of indels in noncoding DNA sequences from sex chromosomes. The rates are similar on the X and Y chromosomes of primates but about twice as high on the avian Z chromosome as on the W chromosome. The fact that indels are not uncommon on the nonrecombining Y and W chromosomes excludes meiotic crossing over as the main cause of indel mutation. On the other hand, the similar rates on X and Y indicate that the number of DNA replications (higher for Y than for X) is also not the main factor. Our observations are therefore consistent with a role of both DNA replication and recombination in the generation of short insertion and deletion mutations. A significant excess of deletion compared to insertion events is observed on the avian W chromosome, consistent with gradual DNA loss on a nonrecombining chromosome.


2021 ◽  
pp. 1-11
Author(s):  
David S. da Silva ◽  
Heriberto F. da Silva Filho ◽  
Marcelo B. Cioffi ◽  
Edivaldo H.C. de Oliveira ◽  
Anderson J.B. Gomes

With 82 species currently described, the genus <i>Leptodactylus</i> is the most diverse and representative one in the family Leptodactylidae. Concerning chromosomal organization, this genus represents an interesting and underexplored group since data from molecular cytogenetics are incipient, and little is known about the organization and distribution of repetitive DNA elements in the karyotypes. In this sense, this study aimed at providing a comparative analysis in 4 <i>Leptodactylus</i> species (<i>L. macrosternum, L. pentadactylus, L. fuscus,</i> and <i>Leptodactylus</i> cf<i>. podicipinus</i>), combining conventional cytogenetics (Giemsa staining, C-banding, and AgNOR staining) and mapping of molecular markers (18S rDNA, telomeric and microsatellite probes), to investigate mechanisms underlying their karyotype differentiation process. The results showed that all species had karyotypes with 2n = 22 and FN = 44, except for <i>Leptodactylus</i> cf. <i>podicipinus</i> which presented FN = 36. The 18S rDNA was observed in pair 8 of all analyzed species (corresponding to pair 4 in <i>L. pentadactylus</i>), coinciding with the secondary constrictions and AgNOR staining. FISH with microsatellite DNA probes demonstrated species-specific patterns, as well as an association of these repetitive sequences with constitutive heterochromatin blocks and ribosomal DNA clusters, revealing the dynamics of microsatellites in the genome of the analyzed species. In summary, our data demonstrate an ongoing process of genomic divergence inside species with almost similar karyotype, driven most likely by a series of pericentric inversions, followed by differential accumulation of repetitive sequences.


1990 ◽  
Vol 3 (1) ◽  
pp. 145
Author(s):  
DJ Colgan

This paper is a review of the use of information regarding the presence of duplicate genes and their regulation in systematics. The review concentrates on data derived from protein electrophoresis and restriction fragment length polymorphism analysis. The appearance of a duplication in a subset of a group of species implies that the members of the subset belong to the same clade. Suppression of the duplication may render this clade apparently paraphyletic, but may itself be informative of relations within the lineage through patterns of loss of expression in all, or some tissues, or through restrictions of the formation of functional heteropolymers in polymeric enzymes. Examples are given of studies which have used such information to establish phylogenetic hypotheses at the family level, to identify an auto- or allo-polyploid origin of polyploid species and to determine whether there have been single or multiple origins of such species. The likelihood of homoplasy in the patterns of appearance and regulation of duplicates depends on the molecular basis of the duplication. In particular, the contrast between the expected consequences of tandem duplication and the expression of pseudogenes emphasises the value of determining the mechanism of the original duplication. Many instances of sporadic gene duplication are now known, and polyploidisation is a common event in the evolutionary history of both plants and animals. So the opportunities to discover duplicationrelated characters will arise in many systematic studies. A program is presented to increase the chances that such useful information will be recognisable during the studies.


2005 ◽  
Vol 1 (3) ◽  
pp. 291-295 ◽  
Author(s):  
Jennifer A Leonard ◽  
Nadin Rohland ◽  
Scott Glaberman ◽  
Robert C Fleischer ◽  
Adalgisa Caccone ◽  
...  

Twenty years ago, the field of ancient DNA was launched with the publication of two short mitochondrial (mt) DNA sequences from a single quagga ( Equus quagga ) museum skin, an extinct South African equid ( Higuchi et al . 1984 Nature 312 , 282–284). This was the first extinct species from which genetic information was retrieved. The DNA sequences of the quagga showed that it was more closely related to zebras than to horses. However, quagga evolutionary history is far from clear. We have isolated DNA from eight quaggas and a plains zebra (subspecies or phenotype Equus burchelli burchelli ). We show that the quagga displayed little genetic diversity and very recently diverged from the plains zebra, probably during the penultimate glacial maximum. This emphasizes the importance of Pleistocene climate changes for phylogeographic patterns in African as well as Holarctic fauna.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Masahiko Muraji ◽  
Norio Arakaki ◽  
Shigeo Tanizaki

The phylogenetic relationship, biogeography, and evolutionary history of closely related two firefly species,Curtos costipennisandC. okinawanus, distributed in the Ryukyu Islands of Japan were examined based on nucleotide sequences of mitochondrial (2.2 kb long) and nuclear (1.1-1.2 kb long) DNAs. In these analyses, individuals were divided among three genetically distinct local groups,C. costipennisin the Amami region,C. okinawanusin the Okinawa region, andC. costipennisin the Sakishima region. Their mtDNA sequences suggested that ancestralC. costipennispopulation was first separated between the Central and Southern Ryukyu areas, and the northern half was then subdivided betweenC. costipennisin the Amami andC. okinawanusin the Okinawa. The application of the molecular evolutionary clocks of coleopteran insects indicated that their vicariance occurred 1.0–1.4 million years ago, suggesting the influence of submergence and subdivision of a paleopeninsula extending between the Ryukyu Islands and continental China through Taiwan in the early Pleistocene.


1993 ◽  
Vol 67 (4) ◽  
pp. 549-570 ◽  
Author(s):  
Bruce S. Lieberman

Phylogenetic parsimony analysis was used to classify the Siegenian–Eifelian “Metacryphaeus group” of the family Calmoniidae. Thirty-eight exoskeletal characters for 16 taxa produced a shortest-length cladogram with a consistency index of 0.49. A classification based on retrieving the structure of this cladogram recognizes nine genera: Typhloniscus Salter, Plesioconvexa n. gen., Punillaspis Baldis and Longobucco, Eldredgeia n. gen., Clarkeaspis n. gen., Malvinocooperella n. gen., Wolfartaspis Cooper, Plesiomalvinella Lieberman, Edgecombe, and Eldredge (used to represent the malvinellid clade), and Metacryphaeus Reed. The malvinellid clade is most closely related to a revised monophyletic Metacryphaeus. Typhloniscus is the basal member of the “Metacryphaeus group,” and the monotypic Wolfartaspis is sister to the clade containing the malvinellids and Metacryphaeus. Six new species are diagnosed: Punillaspis n. sp. A, “Clarkeaspis” gouldi, Clarkeaspis padillaensis, Malvinocooperella pregiganteus, Metacryphaeus curvigena, and Metacryphaeus branisai. Primitively, this group has South African and Andean affinities, and its evolutionary history suggests rapid diversification. In addition, evolutionary patterns in this group, and the distribution of character reversals, call into question certain notions about the nature of adaptive radiations. The distributions of taxa may answer questions about the number of marine transgressive/regressive cycles in the Emsian–Eifelian of the Malvinokaffric Realm.


2021 ◽  
Author(s):  
Keerthic Aswin ◽  
Srinivasan Ramachandran ◽  
Vivek T Natarajan

AbstractEvolutionary history of coronaviruses holds the key to understand mutational behavior and prepare for possible future outbreaks. By performing comparative genome analysis of nidovirales that contain the family of coronaviruses, we traced the origin of proofreading, surprisingly to the eukaryotic antiviral component ZNFX1. This common recent ancestor contributes two zinc finger (ZnF) motifs that are unique to viral exonuclease, segregating them from DNA proof-readers. Phylogenetic analyses indicate that following acquisition, genomes of coronaviruses retained and further fine-tuned proofreading exonuclease, whereas related families harbor substitution of key residues in ZnF1 motif concomitant to a reduction in their genome sizes. Structural modelling followed by simulation suggests the role of ZnF in RNA binding. Key ZnF residues strongly coevolve with replicase, and the helicase involved in duplex RNA unwinding. Hence, fidelity of replication in coronaviruses is a result of convergent evolution, that enables maintenance of genome stability akin to cellular proofreading systems.


1984 ◽  
Vol 8 ◽  
pp. 182-198
Author(s):  
Catherine Badgley

The evolutionary history of humans is well understood in outline, compared to that of many other groups of mammals. But human evolution remains enigmatic in its details, and these are compelling both scientifically and personally because they relate to the biological uniqueness of humans. Humans are placed in the primate family Hominidae, which, in traditional classifications, contains a single living species, Homo sapiens. The closest living relatives of humans are great apes: the chimpanzees Pan paniscus and Pan troglodytes, the gorilla Gorilla gorilla, and the orangutan Pongo pygmaeus. These apes have traditionally been placed in the family Pongidae as the sister group of Hominidae. Living Hominidae and Pongidae, together with Hylobatidae (gibbons) comprise the modern representatives of the primate suborder Hominoidea.


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