scholarly journals Karyotype of Polyommatus (Agrodiaetus) eriwanensis Forster, 1960 and taxonomic position of P. (A.) interjectus de Lesse, 1960 (Lepidoptera, Lycaenidae)

2019 ◽  
Vol 13 (4) ◽  
pp. 359-366
Author(s):  
Vladimir Lukhtanov ◽  
Alexander Dantchenko
Keyword(s):  
Male Meiosis ◽  
Lower Number ◽  
Taxonomic Position ◽  
Type Locality ◽  
Allopatric Distribution ◽  
Multivalent Formation ◽  
Meiosis I

The karyotype of Polyommatus (Agrodiaetus) eriwanensis Forster, 1960 from the type locality (“Eriwan” [Yerevan, Armenia]) and other localities in Armenia was investigated. The number of chromosomal elements (bivalents+ multivalents) observed in male meiosis I was found to vary from 29 to 34. In individuals with n = 34, all observed elements were represented by bivalents. In other specimens, heterozygosity for different number of chromosomal fusions resulted in multivalent formation at MI stage and consequently in a lower number of recognizable chromosomal elements. We show that all karyotype peculiarities of P. (A.) interjectus de Lesse, 1960 (n = 29–32) from Turkey are similar to those in A. eriwanensis. The butterflies of these taxa have allopatric distribution and can be considered as conspecific.

Role of microtubules and microtubule organizing centers on meiotic chromosome elimination in Sciara ocellaris

1997 ◽  
Vol 110 (6) ◽  
pp. 721-730 ◽  
Author(s):  
M.R. Esteban ◽  
M.C. Campos ◽  
A.L. Perondini ◽  
C. Goday
Keyword(s):  
Meiotic Chromosome ◽  
Chromosome Elimination ◽  
Male Meiosis ◽  
Meiotic Spindle ◽  
Monopolar Spindle ◽  
Meiotic Spindles ◽  
Cytoplasmic Microtubules ◽  
Spindle Microtubules ◽  
Meiosis I

Spindle formation and chromosome elimination during male meiosis in Sciara ocellaris (Diptera, Sciaridae) has been studied by immunofluorescence techniques. During meiosis I a monopolar spindle is formed from a single polar complex (centrosome-like structure). This single centrosomal structure persists during meiosis II and is responsible for the non-disjunction of the maternal X chromatids. During meiosis I and II non-spindle microtubules are assembled in the cytoplasmic bud regions of the spermatocytes. The chromosomes undergoing elimination during both meiotic divisions are segregated to the bud region where they associate with bundles of microtubules. The presence and distribution of centrosomal antigens in S. ocellaris meiotic spindles and bud regions has been investigated using different antibodies. gamma-Tubulin and centrin are present in the bud as well as in the single polar complex of first meiotic spindle. The results suggest that spermatocyte bud regions contain microtubule-organizing centres (MTOCs) that nucleate cytoplasmic microtubules that are involved in capturing chromosomes in the bud regions. The distribution of actin and myosin in the spermatocytes during meiosis is also reported.

scholarly journals Chromosome separation during Drosophila male meiosis I requires separase-mediated cleavage of the homolog conjunction protein UNO

PLoS Genetics ◽  
2020 ◽  
Vol 16 (10) ◽  
pp. e1008928
Author(s):  
Joe Weber ◽  
Zeynep Kabakci ◽  
Soumya Chaurasia ◽  
Erich Brunner ◽  
Christian F. Lehner
Keyword(s):  
Male Meiosis ◽  
Chromosome Separation ◽  
Meiosis I

scholarly journals Taxonomic status and additional description of White’s Stalked-eyed Fly Cyrtodiopsis whitei (Curran, 1936) (Diptera: Diopsidae) from India with a key to the allied species and note on its habitat

2018 ◽  
Vol 10 (8) ◽  
pp. 12035
Author(s):  
Basant Kumar Agarwala
Keyword(s):  
Deciduous Forest ◽  
Taxonomic Status ◽  
Taxonomic Position ◽  
Type Locality ◽  
Eastern India ◽  
Type Specimens ◽  
Male And Female ◽  
Northeastern Part ◽  
Taxonomic Key ◽  
Dry Deciduous Forest

Systematics and ecology of Cyrtodiopsis whitei (Curran, 1936), initially described in brief from a tropical dry deciduous forest in eastern India as Diopsis whitei, remained obscure for want of the type specimens.  Recent collections of male and female specimens of this species from a new locality in the northeastern part of India, the country of the type locality, has allowed a fresh appraisal of its morphology, taxonomic position and habitat ecology in the background of several studies done on Diopsidae.  Herein are included some new characters, hitherto unknown in the species of Cyrtodiopsis, a taxonomic key to the separation of four species, considered monophyletic under the genus, and a note on the habitat of the species.

On some Afrotropical Harpalus, with description of two new species, and remarks on Hypharpax australis (Coleoptera: Carabidae): misidentification, mislabeling, and introduction to the Australian region

Zootaxa ◽  
2021 ◽  
Vol 5020 (1) ◽  
pp. 31-56
Author(s):  
BORIS M. KATAEV
Keyword(s):  
New Species ◽  
New Zealand ◽  
East Africa ◽  
Taxonomic Position ◽  
Type Locality ◽  
African Continent ◽  
Additional Material ◽  
Diagnostic Characters ◽  
Two New Species ◽  
The Status

New data on taxonomy of several Afrotropical species of Harpalus Latreille, 1802 are provided, with special attention to the species recorded outside the African continent. Two new species from East Africa are described: H. pseudoasemus sp. n. from Tanzania and Kenya (type locality: Oldonyo Dambu, 15 km north of Arusha, Tanzania), and H. merkli sp. n. from Ethiopia (type locality: Chercher). Harpalus impressus Roth, 1851, H. asemus Basilewsky, 1947, H. fuscoaeneus Dejean, 1829, H. australasiae Dejean, 1829, and H. parvulus Dejean, 1829 are re-described based on the types and additional material, and the diagnostic characters of Hypharpax australis (Dejean, 1829) are given. Harpalus australasiae sensu Larochelle & Larivière, 2005 (non Dejean, 1829) is treated as conspecific with the Afrotropical H. parvulus which was introduced to Australia and New Zealand. The genus Anisochirus Jeannel, 1946, stat. resurr. is restored for most of the Madagascan and Mascarene species included previously in Harpalus. The members of this genus differ from those of Harpalus in having glabrous paraglossae. The status and taxonomic position of Anisochirus is discussed. The following synonymies are proposed: Harpalus impressus Roth, 1851 = H. sundaicus Schauberger, 1933, syn. n., and H. asemus Basilewsky, 1947 (January 30) = H. hamasiensis G. Müller, 1947 (September 30), syn. n. Lectotypes are designated for H. impressus and H. fuscoaeneus.  

Incongruence between taxonomy and genetics: three divergent lineages within two subspecies of the rare Transcaucasian rat snake (Zamenis hohenackeri)

2013 ◽  
Vol 34 (4) ◽  
pp. 579-584 ◽  
Author(s):  
David Jandzik ◽  
Aziz Avcı ◽  
Václav Gvoždík
Keyword(s):  
Genetic Variation ◽  
Mitochondrial Gene ◽  
Type Locality ◽  
Nw Iran ◽  
Caucasus Region ◽  
The Third ◽  
Allopatric Distribution ◽  
Rat Snake

Two morphologically differentiated subspecies with presumably allopatric distribution have traditionally been recognized in the rare Transcaucasian rat snake, Zamenis hohenackeri: Z. h. hohenackeri (Caucasus region and E Turkey, NW Iran and N Iraq) and Z. h. tauricus (S Anatolia and Levant). Both subspecies are sometimes considered just colour forms of a monotypic species. We used sequences of the mitochondrial gene cytochrome b to find out whether both subspecies are also genetically differentiated, or whether their haplotypes form a cluster without clear subdivision. We found that the species forms three divergent lineages: one corresponds to the nominotypic subspecies, another comprises an individual from the region of the type locality of Z. h. tauricus in southern Anatolia and the third, with no available name and separated from the previous by the Amanos (Nur) Mountains, is distributed in the Levant. The pattern of divergence and distribution of the lineages correspond to other species of amphibians and reptiles, demonstrating that similar geo-climatic events presumably formed genetic variation and triggered speciation processes in this region.

Cold stress contributes to aberrant cytokinesis during male meiosis I in a wheat thermosensitive genic male sterile line

2010 ◽  
Vol 34 (3) ◽  
pp. 389-405 ◽  
Author(s):  
ZONGHUI TANG ◽  
LIPING ZHANG ◽  
DI YANG ◽  
CHANGPING ZHAO ◽  
YONGLIAN ZHENG
Keyword(s):  
Cold Stress ◽  
Male Meiosis ◽  
Male Sterile ◽  
Male Sterile Line ◽  
Meiosis I

scholarly journals Bipolar spindle attachments affect redistributions of ZW10, a Drosophila centromere/kinetochore component required for accurate chromosome segregation.

1996 ◽  
Vol 134 (5) ◽  
pp. 1127-1140 ◽  
Author(s):  
B C Williams ◽  
M Gatti ◽  
M L Goldberg
Keyword(s):  
Chromosome Segregation ◽  
Male Meiosis ◽  
Chromosome Behavior ◽  
Bipolar Spindle ◽  
Chromosome Missegregation ◽  
Spindle Poles ◽  
Anaphase Onset ◽  
Sister Chromatids ◽  
Chromosome Separation ◽  
Meiosis I

Previous efforts have shown that mutations in the Drosophila ZW10 gene cause massive chromosome missegregation during mitotic divisions in several tissues. Here we demonstrate that mutations in ZW10 also disrupt chromosome behavior in male meiosis I and meiosis II, indicating that ZW10 function is common to both equational and reductional divisions. Divisions are apparently normal before anaphase onset, but ZW10 mutants exhibit lagging chromosomes and irregular chromosome segregation at anaphase. Chromosome missegregation during meiosis I of these mutants is not caused by precocious separation of sister chromatids, but rather the nondisjunction of homologs. ZW10 is first visible during prometaphase, where it localizes to the kinetochores of the bivalent chromosomes (during meiosis I) or to the sister kinetochores of dyads (during meiosis II). During metaphase of both divisions, ZW10 appears to move from the kinetochores and to spread toward the poles along what appear to be kinetochore microtubules. Redistributions of ZW10 at metaphase require bipolar attachments of individual chromosomes or paired bivalents to the spindle. At the onset of anaphase I or anaphase II, ZW10 rapidly relocalizes to the kinetochore regions of the separating chromosomes. In other mutant backgrounds in which chromosomes lag during anaphase, the presence or absence of ZW10 at a particular kinetochore predicts whether or not the chromosome moves appropriately to the spindle poles. We propose that ZW10 acts as part of, or immediately downstream of, a tension-sensing mechanism that regulates chromosome separation or movement at anaphase onset.

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