Chromosome morphology in Gilbert's potoroo, Potorous gilbertii (Marsupialia : Potoroidae)

2000 ◽  
Vol 48 (3) ◽  
pp. 281 ◽  
Author(s):  
E. A. Sinclair ◽  
A. R. Murch ◽  
M. Di Renzo ◽  
M. Palermo
Keyword(s):  
Phylogenetic Analysis ◽  
Sex Chromosomes ◽  
Karyotype Evolution ◽  
Chromosome Morphology ◽  
Evolutionary Relationships ◽  
Giemsa Banding ◽  
Banding Patterns ◽  
Multiple Gene ◽  
Male And Female ◽  
Evolution Of Karyotypes

Chromosome morphology was examined for male and female Gilbert’s potoroo, Potorous gilbertii, to infer taxonomic and evolutionary relationships among the extant taxa within the genus Potorous. P. gilbertii has the same number of chromosomes as P. tridactylus, 2n = 12,13. Giemsa-banding patterns were very similar in P. gilbertii and P. tridactylus; however, differences were noted between the sex chromosomes. Given that the relationships among extant Potorous are unresolved, we mapped karyotypes onto two alternative phylogenies to suggest methods of karyotype evolution within this group. Karyotypes and molecular-based information from the now ‘presumed extinct’ P. platyops or sequencing of multiple gene regions for phylogenetic analysis within the Potoroidae would provide valuable information for resolving the issue of rooting, and hence drawing conclusions on the evolution of karyotypes within this group.

scholarly journals Differences in recombination frequencies during female and male meioses of the sex chromosomes of the medaka, Oryzias latipes

2001 ◽  
Vol 78 (1) ◽  
pp. 23-30 ◽  
Author(s):  
MARIKO KONDO ◽  
ERIKO NAGAO ◽  
HIROSHI MITANI ◽  
AKIHIRO SHIMA
Keyword(s):  
Genetic Map ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Oryzias Latipes ◽  
Male Recombination ◽  
Male And Female ◽  
Y Chromosomes ◽  
Genetic Length ◽  
Expressed Sequence ◽  
Group 1

In the medaka, Oryzias latipes, sex is determined chromosomally. The sex chromosomes differ from those of mammals in that the X and Y chromosomes are highly homologous. Using backcross panels for linkage analysis, we mapped 21 sequence tagged site (STS) markers on the sex chromosomes (linkage group 1). The genetic map of the sex chromosome was established using male and female meioses. The genetic length of the sex chromosome was shorter in male than in female meioses. The region where male recombination is suppressed is the region close to the sex-determining gene y, while female recombination was suppressed in both the telomeric regions. The restriction in recombination does not occur uniformly on the sex chromosome, as the genetic map distances of the markers are not proportional in male and female recombination. Thus, this observation seems to support the hypothesis that the heterogeneous sex chromosomes were derived from suppression of recombination between autosomal chromosomes. In two of the markers, Yc-2 and Casp6, which were expressed sequence-tagged (EST) sites, polymorphisms of both X and Y chromosomes were detected. The alleles of the X and Y chromosomes were also detected in O. curvinotus, a species related to the medaka. These markers could be used for genotyping the sex chromosomes in the medaka and other species, and could be used in other studies on sex chromosomes.

A cladistic revision of Tortopus Needham & Murphy with description of the new genus Tortopsis (Ephemeroptera: Polymitarcyidae)

Zootaxa ◽  
2010 ◽  
Vol 2481 (1) ◽  
Author(s):  
CARLOS MOLINERI
Keyword(s):  
Phylogenetic Analysis ◽  
Fore Wing ◽  
Type Species ◽  
New Genus ◽  
Lateral View ◽  
Median Line ◽  
Male And Female ◽  
Line Drawings ◽  
Neotropical Species ◽  
First Time

The 12 species previously placed in Tortopus together with 3 species newly described here, are revised and included in a phylogenetic analysis. Based on synapomorphic characters on the nymphs and adults of both sexes, Tortopus is restricted to T. igaranus Needham & Murphy, T. circumfluus Ulmer, T. harrisi Traver, T. zottai (Navás), T. bellus Lugo-Ortiz & McCafferty, and T. arenales sp. nov., and the genus is defined by: female parastyli receptors with long furrows anterior to sockets; penes entirely flattened; male ninth abdominal sternum almost separated in two portions by a median notch; mesosternum with furcasternal protuberances contiguous only on basal corner; and nymphs with two subapical tubercles on mandibular tusks. Tortopsis is newly described for T. bruchianus (Navás), T. limoncocha sp. nov., T. obscuripennis (Domínguez), T. parishi (Banks), T. primus (McDunnough), T. puella (Pictet), T. sarae (Domínguez), T. spatula sp. nov., and T. unguiculatus (Ulmer). Tortopsis is characterized by: R sector of female fore wing without additional veins between R 2 and IR; female parastyli receptors C or V-shaped, with sockets opening towards median line; male gonopore associated with a claw-like structure; penes separated from the base; parastyli more than 5 times length of pedestals; parastyli curved in lateral view; nymphs with a single subapical tubercle on mandibular tusks. The study of available type material permitted inclusion of comparative diagnoses, with figures and redescriptions as needed. The male imago of the type species of Tortopus (T. igaranus Needham & Murphy) is described for the first time, as are the female adults of Tortopus bellus Lugo-Ortiz & McCafferty and T. harrisi Traver. Three new Neotropical species based on male and female adults are described: Tortopus arenales and Tortopsis limoncocha from Ecuador, and Tortopsis spatula from Colombia. Keys to separate the adults and nymphs of the genera of Polymitarcyidae, and for male and female adults of all the species of Tortopus and Tortopsis are presented, as well as line drawings, pictures and SEM photographs of important structures.

scholarly journals Do male and female heterogamety really differ in expression regulation? Lack of global dosage balance in pygopodid geckos

2021 ◽  
Vol 376 (1833) ◽  
pp. 20200102 ◽  
Author(s):  
Michail Rovatsos ◽  
Tony Gamble ◽  
Stuart V. Nielsen ◽  
Arthur Georges ◽  
Tariq Ezaz ◽  
...  
Keyword(s):  
Sex Determination ◽  
Sex Chromosomes ◽  
Gene Dosage ◽  
Regulatory Mechanisms ◽  
Gene Copy ◽  
Male And Female ◽  
Gene Dose ◽  
Female Heterogamety ◽  
Dosage Balance ◽  
Male Heterogamety

Differentiation of sex chromosomes is thought to have evolved with cessation of recombination and subsequent loss of genes from the degenerated partner (Y and W) of sex chromosomes, which in turn leads to imbalance of gene dosage between sexes. Based on work with traditional model species, theory suggests that unequal gene copy numbers lead to the evolution of mechanisms to counter this imbalance. Dosage compensation, or at least achieving dosage balance in expression of sex-linked genes between sexes, has largely been documented in lineages with male heterogamety (XX/XY sex determination), while ZZ/ZW systems are assumed to be usually associated with the lack of chromosome-wide gene dose regulatory mechanisms. Here, we document that although the pygopodid geckos evolved male heterogamety with a degenerated Y chromosome 32–72 Ma, one species in particular, Burton's legless lizard ( Lialis burtonis ), does not possess dosage balance in the expression of genes in its X-specific region. We summarize studies on gene dose regulatory mechanisms in animals and conclude that there is in them no significant dichotomy between male and female heterogamety. We speculate that gene dose regulatory mechanisms are likely to be related to the general mechanisms of sex determination instead of type of heterogamety. This article is part of the theme issue ‘Challenging the paradigm in sex chromosome evolution: empirical and theoretical insights with a focus on vertebrates (Part II)’.

A phylogenetic revision of Calydna and relatives (Lepidoptera: Riodinidae)

2002 ◽  
Vol 33 (2) ◽  
pp. 185-237 ◽  
Author(s):  
Jason P.W. Hall
Keyword(s):  
Phylogenetic Analysis ◽  
New Genus ◽  
Male And Female ◽  
Basal Clade ◽  
Two New Species ◽  
Group A ◽  
Species Groups ◽  
First Time ◽  
The Relationship ◽  
Phylogenetic Revision

AbstractA phylogenetic revision of the Neotropical riodinid genus Calydna Doubleday and relatives is presented. A phylogenetic analysis for all twenty species of Calydna using thirty-eight characters of adult morphology generated four most parsimonious cladograms. Calydna is characterised to contain eighteen species, divided here into three monophyletic species groups with the relationship caieta group + (thersander group + hiria group). A new genus Echydna Hall gen. n. is described for the most basal clade, containing chaseba Hewitson and punctata C. & R. Felder, which are transferred from Calydna (combs. n.). The taxonomy, morphology, biogeography and biology of both genera are discussed, locality data is listed and mapped, and the adults and male and female genitalia are illustrated for all species. Concealed male abdominal androconial scales, which phylogenetically unite the thersander and hiria groups, are reported for the first time outside of the tribes Symmachiini and Nymphidiini. Two new species are described, Calydna jeannea sp. n. and Calydna nicolayi sp. n., and the replacement name fissilisima is provided for the unavailable name fissilis Stichel; maculosa Bates is transferred from Calydna to Callistium Stichel (comb. n.).

Giemsa C-banded karyotypes of Hordeum marinum and H. murinum

Genome ◽  
1989 ◽  
Vol 32 (4) ◽  
pp. 629-639 ◽  
Author(s):  
Ib Linde-Laursen ◽  
Roland von Bothmer ◽  
Niels Jacobsen
Keyword(s):  
Chromosome Morphology ◽  
Similar Distribution ◽  
Banding Patterns ◽  
Homologous Chromosomes ◽  
C Banding ◽  
Linear Relationships ◽  
Close Relationship ◽  
Different Populations ◽  
Pattern Polymorphism ◽  
Hordeum Species

Giemsa C-banding patterns of the predominantly self-pollinating, annual species Hordeum marinum (2x, 4x) and H. murinum (2x, 4x, 6x) showed mostly very small to small bands at centromeric and telomeric positions, at one or both sides of the nucleolar constrictions, and at intercalary positions with no preferential disposition. A similar distribution of bands has been observed in other Hordeum species, suggesting that the pattern is the basic one in the genus Hordeum. Hordeum murinum, especially the hexaploid cytotype, was distinguished from H. marinum by having more numerous and more conspicuous bands, resulting in a significantly higher percentage of constitutive heterochromatin (9–17 vs. 4–8%). The differences in C-banding patterns supported by differences in chromosome morphology confirm that H. marinum and H. murinum are not closely related. Banding-pattern polymorphism was prevalent among populations but unobserved within populations. In spite of this polymorphism, banding patterns in combination with chromosome morphology identified homologous chromosomes of different populations of a taxon and indicated that the chromosome complements of the polyploids of both species comprised the genome of the related diploid as well as one or two "unidentified" genomes. This agrees with an alloploid origin of polyploids. The C-banding patterns of H. marinum ssp. marinum and H. marinum ssp. gussoneanum (2x) showed some divergence in spite of the close relationship. The C-banded karyotypes of H. murinum ssp. murinum and H. murinum ssp. leporinum (4x) were very similar, supporting conspecificity. Chromosome lengths and longest/shortest chromosome ratios were fairly similar to those previously published, supporting the conclusion that linear relationships of chromosomes are normally stable within genomes. The taxonomy of the two species is discussed.Key words: C-banding, karyotypes, Hordeum.

Pattern of X-Y chromosome pairing in the Taiwan vole, Microtus kikuchii

Genome ◽  
2001 ◽  
Vol 44 (1) ◽  
pp. 27-31 ◽  
Author(s):  
K Mekada ◽  
M Harada ◽  
L K Lin ◽  
K Koyasu ◽  
P M Borodin ◽  
...  
Keyword(s):  
Synaptonemal Complex ◽  
Chromosome Pairing ◽  
Sex Chromosomes ◽  
Meiotic Prophase ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
The Other ◽  
Banding Patterns ◽  
Y Chromosomes

Pairing of X and Y chromosomes at meiotic prophase and the G- and C-banding patterns and nucleolar organizer region (NOR) distribution were analyzed in Microtus kikuchii. M. kikuchii is closely related to M. oeconomus and M. montebelli, karyologically and systematically. The formation of a synaptonemal complex between the X and Y chromosomes at pachytene and end-to-end association at diakinesis – metaphase I are only observed in three species in the genus Microtus; M. kikuchii, M. oeconomus, and M. montebelli. All the other species that have been studied so far have had asynaptic X–Y chromosomes. These data confirm that M. kikuchii, M. oeconomus, and M. montebelli are very closely related, and support the separation of asynaptic and synaptic groups on the phylogenetic tree.Key words: Microtus kikuchii, Microtus phylogeny, karyotype, synaptic sex chromosomes, synaptonemal complex.

A redefinition of the genus Troglocharinus Reitter, 1908, with description of new species (Coleoptera, Leiodidae, Cholevinae, Leptodirini)

Zootaxa ◽  
2021 ◽  
Vol 4926 (2) ◽  
pp. 151-188
Author(s):  
JAVIER FRESNEDA ◽  
VALERIA RIZZO ◽  
JORDI COMAS ◽  
IGNACIO RIBERA
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
Phylogenetic Analyses ◽  
Molecular Data ◽  
Valid Species ◽  
Distribution Area ◽  
Undescribed Species ◽  
Separate Species ◽  
Male And Female ◽  
New Material

We redefine the genus Troglocharinus Reitter, 1908 based on a phylogenetic analysis with a combination of mitochondrial and molecular data. We recovered the current Speonomites mengeli (Jeannel, 1910) and S. mercedesi (Zariquiey, 1922) as valid, separate species within the Troglocharinus clade, not directly related to Speonomites Jeannel, 1910, a finding corroborated by a detailed study of the male and female genitalia. In consequence, we reinstate Speonomus mercedesi Zariquiey, 1922 stat. nov. as a valid species, transfer both of them to the genus Troglocharinus, T. mengeli (Jeannel, 1910) comb. nov. and T. mercedesi (Zariquiey, 1922) comb. nov., and redescribe the genus. The study of new material from the distribution area of the former S. mengeli revealed the presence of two undescribed species, T. sendrai sp. nov. and T. fadriquei sp. nov., which we describe herein. We designate the lectotype of Speonomus vinyasi Escolà, 1971 to fix its identity, as among its syntypes there are two different species. In agreement with the results of the phylogenetic analyses we establish the synonymy between the genus Speonomites and Pallaresiella Fresneda, 1998 syn. nv. 

Clidicus minilankanus sp. n., with notes on remaining Sri Lankan Clidicus species (Coleoptera, Staphylinidae, Scydmaeninae)

Zootaxa ◽  
2020 ◽  
Vol 4718 (1) ◽  
pp. 87-94
Author(s):  
PAWEŁ JAŁOSZYŃSKI
Keyword(s):  
Phylogenetic Analysis ◽  
Sri Lanka ◽  
Junior Synonym ◽  
Monophyletic Group ◽  
Evolutionary Relationships ◽  
Sri Lankan

Until now, four species of Clidicus Laporte were found in Sri Lanka, three known from female specimens only. Clidicus minilankanus sp. n., is described, and compared to all remaining sympatric congeners. The Sri Lankan species may form a monophyletic group characterized by several morphological oddities: the head only slightly impressed posteromedially, with a large portion of vertex and frons not divided longitudinally; the pronotum quadrangular and flattened, with vestigial or absent posterior ‘collar’, and the transverse groove that demarcates it from the disc lacking pits or even entirely or partly obliterated; and the metaventrite strongly shortened, so that meso- and metacoxae are nearly adjacent. These characters may justify resurrecting Erineus Walker, a junior synonym of Clidicus (proposed for the first described Sri Lankan species, C. monstrosus (Walker)), as a valid name for a subgenus. This problem must be addressed by a phylogenetic analysis of all Clidicus species, to establish evolutionary relationships within this interesting genus. 

scholarly journals Flightless Disphaerona rediscovered in China: mtDNA phylogeography of the Yunnan clade and the sobering state of fungus weevil phylogenetics (Coleoptera: Anthribidae)

2016 ◽  
Vol 48 (2) ◽  
pp. 89 ◽  
Author(s):  
Vasily V. Grebennikov
Keyword(s):  
Phylogenetic Analysis ◽  
Dna Barcode ◽  
Sister Group ◽  
The State ◽  
Female Genitalia ◽  
Dabie Mountains ◽  
Male And Female ◽  
The Family

This paper reports discovery of the genus <em>Disphaerona</em> Jordan, 1902 in two widely separated regions in China: in three isolated highlands in Yunnan (the Cang Shan Range, Mt. Jizu and Mt. Haba) and in the Dabie Mountains of Hubei, at the border with Anhui. Till present the genus was known from China only from four specimens of<em> D.</em> <em>chinensis</em> (including its holotype) described from Sichuan in 1995. Sixteen specimens from each of the three newly detected localities in Yunnan were DNA barcoded and the data were made publicly available at dx.doi.org/10.5883/DS-DISPHAE. Temporal phylogenetic analysis revealed a topology suggesting monophyly and recent (0.2–0.4 Ma) origin of the populations on both Mt. Jizu and Mt. Haba. The population on the Cang Shan Range harbours representatives of both clades forming the ingroup, mtDNA of which diverged some 7.9 Ma. The habitus of the holotype of the only nominative Chinese <em>Disphaerona</em> species, <em>D. chinensis,</em> is illustrated, together with habitus and male and female genitalia of specimens newly discovered in both Yunnan and Hubei. All specimens of <em>Disphaerona</em> from Yunnan are seemingly conspecific and are taxonomically assigned to D. chinensis. Two similar males and one sympatric but dissimilar, smaller female from the Dabie Mountains do not have associated DNA barcode data. It remains unknown whether the three Dabie Mountains specimens are conspecific or even congeneric; pending this uncertainty they are tentatively treated as <em>Disphaerona</em> without a Linnaean name. <em>Disphaerona</em> population in the Dabie Mountains, if indeed a member of this hypothesised clade, forms the easternmost record of the genus. Monophyly and sister group of <em>Disphaerona</em> are briefly discussed and both are shown as unknown and unverifiable. A brief overview of the state of phylogenetic knowledge of Anthribidae is given, which is practically non-existing and with neither the family, nor any of its tribes and the vast majority of genera tested as monophyletic.

scholarly journals Novel Molecular Synapomorphies Demarcate Different Main Groups/Subgroups of Plasmodium and Piroplasmida Species Clarifying Their Evolutionary Relationships

Genes ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 490 ◽  
Author(s):  
Sharma ◽  
Gupta
Keyword(s):  
Phylogenetic Analysis ◽  
Phylogenetic Trees ◽  
Plasmodium Species ◽  
Protein Sequences ◽  
Evolutionary Relationships ◽  
Major Life ◽  
Comparative Analyses ◽  
Large Numbers ◽  
Conserved Signature Indels ◽  
Relationship Of

The class Hematozoa encompasses several clinically important genera, including Plasmodium, whose members cause the major life-threating disease malaria. Hence, a good understanding of the interrelationships of organisms from this class and reliable means for distinguishing them are of much importance. This study reports comprehensive phylogenetic and comparative analyses on protein sequences on the genomes of 28 hematozoa species to understand their interrelationships. In addition to phylogenetic trees based on two large datasets of protein sequences, detailed comparative analyses were carried out on the genomes of hematozoa species to identify novel molecular synapomorphies consisting of conserved signature indels (CSIs) in protein sequences. These studies have identified 79 CSIs that are exclusively present in specific groups of Hematozoa/Plasmodium species, also supported by phylogenetic analysis, providing reliable means for the identification of these species groups and understanding their interrelationships. Of these CSIs, six CSIs are specifically shared by all hematozoa species, two CSIs serve to distinguish members of the order Piroplasmida, five CSIs are uniquely found in all Piroplasmida species except B. microti and two CSIs are specific for the genus Theileria. Additionally, we also describe 23 CSIs that are exclusively present in all genome-sequenced Plasmodium species and two, nine, ten and eight CSIs which are specific for members of the Plasmodium subgenera Haemamoeba, Laverania, Vinckeia and Plasmodium (excluding P. ovale and P. malariae), respectively. Additionally, our work has identified several CSIs that support species relationships which are not evident from phylogenetic analysis. Of these CSIs, one CSI supports the ancestral nature of the avian-Plasmodium species in comparison to the mammalian-infecting groups of Plasmodium species, four CSIs strongly support a specific relationship of species between the subgenera Plasmodium and Vinckeia and three CSIs each that reliably group P. malariae with members of the subgenus Plasmodium and P. ovale within the subgenus Vinckeia, respectively. These results provide a reliable framework for understanding the evolutionary relationships among the Plasmodium/Piroplasmida species. Further, in view of the exclusivity of the described molecular markers for the indicated groups of hematozoa species, particularly large numbers of unique characteristics that are specific for all Plasmodium species, they provide important molecular tools for biochemical/genetic studies and for developing novel diagnostics and therapeutics for these organisms.

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