scholarly journals Karyotypes and Morphological Variability of Crayfish Pontastacus Leptodactylus and P. Angulosus (Malacostraca, Decapoda)

2013 ◽  
Vol 47 (3) ◽  
pp. 11-16 ◽  
Author(s):  
V. S. Kostyuk ◽  
A. V. Garbar ◽  
S. V. Mezhzherin
Keyword(s):  
Chromosome Number ◽  
Meiotic Chromosome ◽  
Morphological Variability ◽  
Nominal Species ◽  
Widespread Species ◽  
Haploid Chromosome Number ◽  
N 93

The existence on the territory of Ukraine of two sympatric widespread species definitely different by their chromosome number was proved based on the meiotic chromosome preparations. Besides the nominal species Pontastacus leptodactylus (Dana, 1852) with modal haploid chromosome number n = 93 we prove the existence of P. angulosus (Rathke, 1837) with n = 88.

scholarly journals A long reads-based de-novo assembly of the genome of the Arlee homozygous line reveals chromosomal rearrangements in rainbow trout

2021 ◽  
Author(s):  
Guangtu Gao ◽  
Susana Magadan ◽  
Geoffrey C Waldbieser ◽  
Ramey C Youngblood ◽  
Paul A Wheeler ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Chromosome Number ◽  
Genome Assembly ◽  
De Novo Assembly ◽  
De Novo ◽  
Sequence Data ◽  
Structural Variations ◽  
High Coverage ◽  
Haploid Chromosome Number ◽  
Long Reads

Abstract Currently, there is still a need to improve the contiguity of the rainbow trout reference genome and to use multiple genetic backgrounds that will represent the genetic diversity of this species. The Arlee doubled haploid line was originated from a domesticated hatchery strain that was originally collected from the northern California coast. The Canu pipeline was used to generate the Arlee line genome de-novo assembly from high coverage PacBio long-reads sequence data. The assembly was further improved with Bionano optical maps and Hi-C proximity ligation sequence data to generate 32 major scaffolds corresponding to the karyotype of the Arlee line (2 N = 64). It is composed of 938 scaffolds with N50 of 39.16 Mb and a total length of 2.33 Gb, of which ∼95% was in 32 chromosome sequences with only 438 gaps between contigs and scaffolds. In rainbow trout the haploid chromosome number can vary from 29 to 32. In the Arlee karyotype the haploid chromosome number is 32 because chromosomes Omy04, 14 and 25 are divided into six acrocentric chromosomes. Additional structural variations that were identified in the Arlee genome included the major inversions on chromosomes Omy05 and Omy20 and additional 15 smaller inversions that will require further validation. This is also the first rainbow trout genome assembly that includes a scaffold with the sex-determination gene (sdY) in the chromosome Y sequence. The utility of this genome assembly is demonstrated through the improved annotation of the duplicated genome loci that harbor the IGH genes on chromosomes Omy12 and Omy13.

scholarly journals Chromosomal and DNA barcode analysis of the Melitaea ala Staudinger, 1881 species complex (Lepidoptera, Nymphalidae)

2021 ◽  
Vol 15 (2) ◽  
pp. 199-216
Author(s):  
Vladimir A. Lukhtanov ◽  
Anastasia V. Gagarina ◽  
Elena A. Pazhenkova
Keyword(s):  
Chromosome Number ◽  
Central Asia ◽  
Species Complex ◽  
Dna Barcode ◽  
Monophyletic Group ◽  
Geographic Proximity ◽  
Haploid Chromosome Number ◽  
East Central ◽  
North East ◽  
Peter The Great

The species of the Melitaea ala Staudinger, 1881 complex are distributed in Central Asia. Here we show that this complex is a monophyletic group including the species, M. ala, M. kotshubeji Sheljuzhko, 1929 and M. enarea Fruhstorfer, 1917. The haploid chromosome number n=29 is found in M. ala and M. kotshubeji and is, most likely, a symplesiomorphy of the M. ala complex. We show that M. ala consists of four subspecies: M. ala zaisana Lukhtanov, 1999 (=M. ala irtyshica Lukhtanov, 1999, syn. nov.) (South Altai, Zaisan Lake valley), M. ala ala (Dzhungarian Alatau), M. ala bicolor Seitz, 1908 (North, East, Central and West Tian-Shan) and M. ala determinata Bryk, 1940 (described from “Fu-Shu-Shi”, China). We demonstrate that M. kotshubeji kotshubeji (Peter the Great Mts in Tajikistan) and M. kotshubeji bundeli Kolesnichenko, 1999 (Alai Mts in Tajikistan and Kyrgyzstan) are distinct taxa despite their geographic proximity in East Tajikistan. Melitaea enarea is widely distributed in the southern part of Central Asia and is sympatric with M. kotshubeji.

Additional information on Meloidogyne polycephannulata and its proposal as a junior synonym of M. incognita

Nematology ◽  
2019 ◽  
Vol 21 (2) ◽  
pp. 129-146
Author(s):  
Jessica M.S. Monteiro ◽  
Vanessa S. Mattos ◽  
Marcilene F.A. Santos ◽  
Ana C.M.M. Gomes ◽  
Valdir R. Correa ◽  
...  
Keyword(s):  
Morphological Variability ◽  
Junior Synonym ◽  
Valid Species ◽  
Bootstrap Support ◽  
Nominal Species ◽  
Aflp Data ◽  
Morphometric Characters ◽  
Additional Information ◽  
Phylogenetic Studies ◽  
Type Population

Summary The type population of Meloidogyne polycephannulata is synonymised with M. incognita based on morphological and morphometric characters, as well as biochemical, molecular and phylogenetic studies. Morphological variability and a wide host range were reported for M. incognita during its first description and later re-description. Meloidogyne polycephannulata was described in Brazil from specimens collected in a carrot field (type population). The esterase phenotype (Est) characterised for this species was identical to the phenotype Est I2 of M. incognita, the most ubiquitous phenotype used for diagnostics. Morphological and morphometric characters of the descriptions of the two nominal species showed major similarities, as well as variability within the range of variation detected in M. incognita. In PCR assays, three SCAR markers species-specific for M. incognita (incK14 F/R, Mi/FR and incB06 F/R) amplified the same fragments of 399 bp, 955 bp and 1200 bp, respectively, for populations in both species. In phylogenetic studies based either on concatenated sequences of ITS1-5.8S-ITS2, D2-D3 rRNA, mitochondrial COII regions or on RAPD and AFLP data, the populations of both species grouped in the same clade with high bootstrap support. Altogether, these results provide congruent evidence that the M. polycephannulata type isolate deposited at the Embrapa Cryopreserved National Collection of Root-knot Nematodes is not a valid species but rather a junior synonym of M. incognita.

Meiotic chromosome behaviour in Cenchrus ciliaris

Bothalia ◽  
1998 ◽  
Vol 28 (1) ◽  
pp. 83-90 ◽  
Author(s):  
N. C. Visser ◽  
J. J. Spies
Keyword(s):  
Chromosome Number ◽  
Meiotic Chromosome ◽  
Basic Chromosome Number ◽  
Chromosome Behaviour ◽  
Meiotic Abnormalities ◽  
Single Specimen ◽  
Cenchrus Ciliaris ◽  
Basic Chromosome ◽  
Single Genome ◽  
Meiotic Irregularities

A basic chromosome number of x = 9 has been confirmed for Cenchrus ciliaris L. Polyploidy is common and levels vary from tetraploid to hexaploid. Aneuploidv is reported for a single specimen, where two chromosomes of a single genome were lost. Various meiotic irregularities were observed. The highest incidence of meiotic abnormalities was observed in the pentaploid specimens. This was attributed to their uneven polyploid level All specimens varied from segmental alloploid to alloploid.

A taxonomic review of the fish parasitic isopod family Cymothoidae Leach, 1818 (Crustacea: Isopoda: Cymothooidea) of India

Zootaxa ◽  
2019 ◽  
Vol 4622 (1) ◽  
pp. 1-99 ◽  
Author(s):  
S. RAVICHANDRAN ◽  
P. VIGNESHWARAN ◽  
G. RAMESHKUMAR
Keyword(s):  
Morphological Variability ◽  
Marine Fishes ◽  
Valid Species ◽  
Indian Species ◽  
Nominal Species ◽  
Host Preferences ◽  
As Species ◽  
The Family ◽  
Species Inquirenda ◽  
Parasitic Isopod

The parasitic isopod family Cymothoidae Leach, 1818 of the India exclusive economic zone is reviewed. A total of 56 nominal species corresponding to 48 valid species belonging to sixteen genera are reviewed from 73 host species belonging to 35 families. Mothocya plagulophora (Haller, 1880), Nerocila depressa Milne Edwards, 1840, Nerocila loveni Bovallius, 1887, Nerocila trichiura (Miers, 1877), Norileca triangulata (Richardson, 1910) and Ryukyua globosa Williams & Bunkley-Williams, 1994 are redescribed. Indusa pustulosa Pillai, 1954 is synonymised with Agarna malayi Tiwari, 1952; Cymothoa krishnai Jayadev Babu & Sanjeeva Raj, 1984 is synonymised with Cymothoa eremita (Brünnich, 1783) and Nerocila priacanthusi Kumari, Rao & Shyamasundari, 1987 is synonymised with Nerocila arres Bowman & Tareen, 1983. Ourozeuktes bopyroides (Lesueur, 1814) is revised and excluded from the Indian fauna. The Indian cymothoid species Agarna bengalensis Kumari, Rao & Shaymasundari, 1990, Cymothoa asymmetrica Pillai, 1954 and Nerocila hemirhamphusi Shyamasundari, Rao & Kumari, 1990 are regarded here as species inquirenda. A key to the Indian genera of the family Cymothoidae and keys to the Indian species of the genera Cymothoa, Joryma, Mothocya, and Nerocila are presented. A checklist of the valid Cymothoidae species until now reported from Indian marine fishes are compiled. Host preferences, morphological variability and distribution are discussed. 

scholarly journals Unprecedented reorganization of holocentric chromosomes provides insights into the enigma of lepidopteran chromosome evolution

2019 ◽  
Vol 5 (6) ◽  
pp. eaau3648 ◽  
Author(s):  
Jason Hill ◽  
Pasi Rastas ◽  
Emily A. Hornett ◽  
Ramprasad Neethiraj ◽  
Nathan Clark ◽  
...  
Keyword(s):  
Chromosome Number ◽  
Chromosome Evolution ◽  
Chromosome Structure ◽  
Holocentric Chromosomes ◽  
Chromosome Counts ◽  
Pieris Napi ◽  
Haploid Chromosome Number ◽  
Genome Wide ◽  
The Face ◽  
Chromosome Level

Chromosome evolution presents an enigma in the mega-diverse Lepidoptera. Most species exhibit constrained chromosome evolution with nearly identical haploid chromosome counts and chromosome-level gene collinearity among species more than 140 million years divergent. However, a few species possess radically inflated chromosomal counts due to extensive fission and fusion events. To address this enigma of constraint in the face of an exceptional ability to change, we investigated an unprecedented reorganization of the standard lepidopteran chromosome structure in the green-veined white butterfly (Pieris napi). We find that gene content in P. napi has been extensively rearranged in large collinear blocks, which until now have been masked by a haploid chromosome number close to the lepidopteran average. We observe that ancient chromosome ends have been maintained and collinear blocks are enriched for functionally related genes suggesting both a mechanism and a possible role for selection in determining the boundaries of these genome-wide rearrangements.

A contribution towards elucidating the life history of Palmaria palmate (=Rhodymenia palmata)

1976 ◽  
Vol 54 (24) ◽  
pp. 2903-2906 ◽  
Author(s):  
J. P. van der Meer
Keyword(s):  
Life History ◽  
Chromosome Number ◽  
Atlantic Coast ◽  
Palmaria Palmata ◽  
Haploid Chromosome Number ◽  
History Of

Palmaria palmata from a region of the Atlantic coast of Canada has been examined cytologically. Plants bearing tetrasporangia were found to be diploid with meiosis occurring in the tetrasporangia. Spermatangial plants and sporelings growing from tetraspores were haploid. The haploid chromosome number appears to be 22–23.

scholarly journals Karyological and morphological variations within the genus Dysphania (Chenopodiaceae) in Bulgaria

2013 ◽  
Vol 72 (1) ◽  
pp. 49-69 ◽  
Author(s):  
Neli H. Grozeva ◽  
Yanka G. Cvetanova
Keyword(s):  
Statistical Analysis ◽  
Chromosome Number ◽  
Quantitative Traits ◽  
Morphological Variability ◽  
Evolutionary Mechanisms ◽  
Qualitative Traits ◽  
Phenotype Variation ◽  
Morphological Variations ◽  
Interpopulation Variation ◽  
Generative Organs

AbstractThe karyological and morphological variability of species from the genus Dysphania were studied. The results demonstrated that genus Dysphania is represented in Bulgaria by five species: Dysphania ambrosioides, D. multifida, D. botrys, D. schraderiana and D. pumilio. The first two species are tetraploids with chromosome number 2n = 32 for D. ambrosioides and 2n = 36 for D. multifida. The remaining three species are diploids with 2n = 18. The results from statistical analysis demonstrated that the main source of phenotype variation in the species is the interpopulation variation. The specific characters which allowed their recognition are themorphological characteristics of the perianth lobes, the upper leaves and the seeds. The distinction between D. multifida, D. ambrosioides and D. schraderiana is based on differences in the quantitative traits, while in D. botrys and D. pumilio qualitative traits are also important. The basic evolutionary mechanisms are polyploidy and diploidy.Atendency towards reduction in the size of generative organs and the number of perianth lobes was found.

Karyotypic analysis of Polymyxa betae (Plasmodiophoromycetes) based on serial thin sections of pachytene nuclei

1983 ◽  
Vol 61 (12) ◽  
pp. 3202-3206 ◽  
Author(s):  
James P. Braselton
Keyword(s):  
Chromosome Number ◽  
Plasmodiophora Brassicae ◽  
Polymyxa Betae ◽  
Karyotypic Analysis ◽  
Thin Sections ◽  
Haploid Chromosome Number ◽  
Synaptonemal Complexes

Three pachytene nuclei of Polymyxa betae Keskin were reconstructed from serial thin sections. Thirty synaptonemal complexes (SCs) were counted, indicating a haploid chromosome number of 30. SCs of Polymyxa were similar to those of Sorosphaera veronicae Schroeter and Membranosorus heterantherae Ostenfeld and Peterson but differed from SCs of Plasmodiophora brassicae Woron. and Woronina pythii Goldie-Smith.

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