Chromosomal diversity in the Australian Phasmatodea

1972 ◽  
Vol 20 (4) ◽  
pp. 445 ◽  
Author(s):  
E Craddock
Keyword(s):  
Chromosome Number ◽  
Sex Chromosome ◽  
Australian Species ◽  
Chromosome Races ◽  
Karyotypic Diversity ◽  
Chromosomal Differentiation ◽  
History Of ◽  
Karyotypic Variation ◽  
Numerical Variation ◽  
Population Structure And Dynamics

A cytological survey of the Australian Phasmatodea, involving 24 species from the five major subfamilies present in Australia, has confirmed earlier indications of the karyotypic diversity of this Order of insects. Male diploid chromosome numbers range from 26 to 45, and XO and XY sex-chromosome mechanisms occur. Whilst being within the overall range of cytological variation already established for the Order, with respect to level of variability, the diversity shown by Australian species exceeds that of previous observations. Numerical variation is present within some species, as well as within subfamilies and genera. The five Australian species which show a geographic pattern of chromosomal differentiation are the first such examples known amongst phasmatids. Didymuria violescens, the most variable, has at least 10 chromosome races, a range in chromosome number from 26 to 39 (2n), and three forms of the sex-chromosome system. Ctenomovpha chronus has at least three chromosome races. It is suggested that the cytological and biological characteristics of this group of insects, including features of their population structure and dynamics, predispose phasmatids to high levels of variability for otherwise conservative chromosome characters. Newly arisen structural rearrangements have been fixed repeatedly in the evolutionary history of the Order. Many of these have resulted in a change in chromosome number; some few have been responsible for XY types of sex mechanism, by incorporation of autosomal material into the primitive XO system. In view of the amount of karyotypic variation present, cytological characters are effectively useless as indicators of broad phylogenetic relationships within the Phasmatodea. Only chromosome size shows some possible correlation with established interrelationships at the subfamily level. The incidence of intraspecific chromosomal differentiation, together with the usual concurrence of chromosomal differences with intrageneric species differences, further suggests that karyotypic differentiation at a racial level may be involved as a normal stage in the speciation pattern of many phasmatids.

scholarly journals Study on clinical and genetic characteristics of male patients with non-obstructive azoospermia

2021 ◽  
Vol 141 (5) ◽  
pp. 39-45
Author(s):  
Nguyen Hoai Bac ◽  
Hoang Long
Keyword(s):  
Sex Chromosome ◽  
Chromosomal Abnormalities ◽  
Klinefelter Syndrome ◽  
Obstructive Azoospermia ◽  
Genetic Characteristics ◽  
Azfc Deletion ◽  
Genetic Abnormalities ◽  
History Of ◽  
Male Patients ◽  
Infertile Patients

We examined 501 patients with non - obstructive azoospermia to evaluate clinical, subclinical, and genetic characteristics. The results show that the average age of patients in the study was 29.8 ± 5.5 years. Primary infertility accounts for the majority, with a rate of 90.3%. There was 38.6% of patients had a history of mumps orchitis. The average levels of FSH, LH, testosterone were 31.6 ± 16.5 mIU/mL, 15.5 ± 10 mIU/mL and 12.8 ± 7.13 nmol/L, respectively. The prevalence of chromosomal abnormalities was 30.7%. Of these, the sex chromosome aneuploidy with 47,XXY karyotype (Klinefelter syndrome) accounted for 27.3%. The incidence of AZF microdeletion was 13.8%. Of these, AZFc deletion was the most common at the rate of 42.1%, AZFa deletion, which accounted for 2.6%, were the least prevalent, and the frequency of AZFd deletion was 5.3%. However, there was no solitary AZFb deletion, which combined with other AZF deletions with 34.2%. Our research shows that mumps orchitis and chromosomal abnormalities are the leading causes of azoospermia. Screening for genetic abnormalities plays an important role in infertile patients with non - obstructive azoospermia.

scholarly journals Karyotypes of three species of Hyperophora Brunner von Wattenwyl, 1878 (Tettigoniidae, Phaneropterinae) enable morphologically similar species to be distinguished

2019 ◽  
Vol 13 (1) ◽  
pp. 87-93 ◽  
Author(s):  
Bruno Cansanção Silva ◽  
Lucas Henrique Bonfim Souza ◽  
Juliana Chamorro-Rengifo ◽  
Douglas Araujo
Keyword(s):  
Chromosome Number ◽  
Diploid Number ◽  
Sex Chromosome ◽  
Acrocentric Chromosome ◽  
Chromosome Morphology ◽  
Similar Species ◽  
Cerrado Biome ◽  
Cytogenetic Studies ◽  
Sex Chromosome System ◽  
The Difference

Phaneropterinae is the largest subfamily of Tettigoniidae, distributed across the globe. There are few cytogenetic studies regarding this group, as in the case of the genus group Aniarae, which represents only two karyotyped species. The current study aims to analyze cytogenetically three species of Hyperophora Brunner von Wattenwyl, 1878 from Brazil. The male diploid number of Hyperophoraminor Brunner von Wattenwyl, 1891 and Hyperophoramajor Brunner von Wattenwyl, 1878 is 2n♂= 31, whereas Hyperophorabrasiliensis Brunner von Wattenwyl, 1878 has shown 2n♂= 29. These three species possess an X0 sex chromosome system and telo/acrocentric chromosome morphology. The only species found in the Pantanal biome, H.brasiliensis, can be chromosomally distinguished from the Cerrado biome species H.major and H.minor, due to the difference in chromosome number (2n♂= 29 and 2n♂= 31, respectively).

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.

Cytoevolutionary Studies in the Genus Bulbine Wolf (Liliaceae) .II. The Australian Annual Taxa (Bulbine semibarbata s.1.)

1986 ◽  
Vol 34 (5) ◽  
pp. 505 ◽  
Author(s):  
EM Watson
Keyword(s):  
Species Richness ◽  
Chromosome Numbers ◽  
The Other ◽  
Root Tip ◽  
Polyploid Complex ◽  
Southwestern Australia ◽  
Australian Species ◽  
Eastern Australia ◽  
Karyotypic Diversity ◽  
Interpopulation Variation

A cytological survey, using root tip mitotic cells and supplemented by some crosses and pollen fertility studies, was carried out on plants of 55 populations of the Australian annual Bulbine sernibarbata s.1. (Liliaceae). There are 4x, 8x and 12.x populations.The 4x forms are almost completely confined to eastern Australia and comprise populations of two kinds: (1) 28-chromosome types, corresponding in morphology to B. alata Baijnath, which to date has had limited taxonomic acceptance; (2) 26-chromosome types with the morphology of B. sernibarbata s. str. The alata form occurs in arid, the sernibarbata in more mesic, areas. The eastern 8x populations are mainly 2n = 54 and are intermediate between the other two taxa in both range and morphology. This suggests an allopolyploid origin based on hybridisation between the alata and sernibarbata types. The western 8x populations are nearly all 2n = 52, with much interpopulation variation in karyotype and a mesic distribution similar to that of the eastern 26-chromosome types. The karyotypic diversity parallels the species richness of other genera in southwestern Australia and indicates that the complex may be older than the corresponding polyploid complex within the perennial B. bulbosa s.1. The 12x (2n =78) populations are confined to arid and transitional rainfall areas of Western Australia. The identification of a distinctive 28-chromosome karyotype for the alata group gives support to the recognition of B. alata Baijnath, and, by providing a logical euploid bridge between the chromosome numbers of the African (2n = 14) and Australian species, strengthens the arguments for treating the two groups as congeneric.

scholarly journals Chromosomal Evolution in the Lizard Genus Varanus (Reptilia)

1975 ◽  
Vol 28 (1) ◽  
pp. 89 ◽  
Author(s):  
Max Kinga ◽  
Dennis King
Keyword(s):  
Chromosome Number ◽  
Pericentric Inversion ◽  
Sex Chromosome ◽  
Chromosomal Rearrangements ◽  
Chromosomal Evolution ◽  
Size Groups ◽  
Sex Chromosome System

The karyotypes have been determined of 16 of the 32 species of the genus Varanus, including animals from Africa, Israel, Malaya and Australia. A constant chromosome number of 2n = 40 was observed. The karyotype is divided into eight pairs of large chromosomes and 12 pairs of microchromosomes. A series of chromosomal rearrangements have become established in both size groups of the karyotype and are restricted to centromere shifts, probably caused by pericentric inversion. Species could be placed in one of six distinct karyotype groups which are differentiated by these rearrangements and whose grouping does not always correspond with the current taxonomy. An unusual sex chromosome system of the ZZjZW type was present in a number of the species examined.

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 ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Evolutionary History ◽  
Karyotype Evolution ◽  
Sex Chromosome ◽  
Repetitive Sequences ◽  
Z Chromosome ◽  
W Chromosome ◽  
The Family ◽  
Agnor Staining ◽  
History Of

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.

scholarly journals In SituGene Mapping of Two Genes Supports Independent Evolution of Sex Chromosomes in Cold-Adapted Antarctic Fish

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Laura Ghigliotti ◽  
C.-H. Christina Cheng ◽  
Céline Bonillo ◽  
Jean-Pierre Coutanceau ◽  
Eva Pisano
Keyword(s):  
Sex Chromosome ◽  
Antarctic Fish ◽  
5S Rdna ◽  
Cold Adapted ◽  
Antifreeze Glycoprotein ◽  
Y Chromosomes ◽  
Pagothenia Borchgrevinki ◽  
History Of ◽  
Sex Chromosome System

Two genes, that is, 5S ribosomal sequences and antifreeze glycoprotein (AFGP) genes, were mapped onto chromosomes of eight Antarctic notothenioid fish possessing a X1X1X2X2/X1X2Y sex chromosome system, namely,Chionodraco hamatusandPagetopsis macropterus(family Channichthyidae),Trematomus hansoni,T. newnesi,T. nicolai,T. lepidorhinus, andPagothenia borchgrevinki(family Nototheniidae), andArtedidraco skottsbergi(family Artedidraconidae). Through fluorescencein situhybridization (FISH), we uncovered distinct differences in the gene content of the Y chromosomes in the eight species, withC. hamatusandP. macropterusstanding out among others in bearing 5S rDNA and AFGP sequences on their Y chromosomes, respectively. Both genes were absent from the Y chromosomes of any analyzed species. The distinct patterns of Y and non-Y chromosome association of the 5S rDNA and AFGP genes in species representing different Antarctic fish families support an independent origin of the sex heterochromosomes in notothenioids with interesting implications for the evolutionary/adaptational history of these fishes living in a cold-stable environment.

Extraordinary and extensive karyotypic variation: A 48-fold range in chromosome number in the gall-inducing scale insect Apiomorpha (Hemiptera: Coccoidea: Eriococcidae)

Genome ◽  
2000 ◽  
Vol 43 (2) ◽  
pp. 255-263 ◽  
Author(s):  
Lyn G Cook
Keyword(s):  
Chromosome Number ◽  
Chromosomal Rearrangements ◽  
Chromosomal Polymorphism ◽  
Chromosomal Evolution ◽  
Scale Insect ◽  
Closely Related Species ◽  
Host Genus ◽  
Species Complexes ◽  
Species Groups ◽  
Karyotypic Variation

Chromosome number reflects strong constraints on karyotype evolution, unescaped by the majority of animal taxa. Although there is commonly chromosomal polymorphism among closely related taxa, very large differences in chromosome number are rare. This study reports one of the most extensive chromosomal ranges yet reported for an animal genus. Apiomorpha Rübsaamen (Hemiptera: Coccoidea: Eriococcidae), an endemic Australian gall-inducing scale insect genus, exhibits an extraordinary 48-fold variation in chromosome number with diploid numbers ranging from 4 to about 192. Diploid complements of all other eriococcids examined to date range only from 6 to 28. Closely related species of Apiomorpha usually have very different karyotypes, to the extent that the variation within some species- groups is as great as that across the entire genus. There is extensive chromosomal variation among populations within 17 of the morphologically defined species of Apiomorpha indicating the existence of cryptic species-complexes. The extent and pattern of karyotypic variation suggests rapid chromosomal evolution via fissions and (or) fusions. It is hypothesized that chromosomal rearrangements in Apiomorpha species may be associated with these insects' tracking the radiation of their speciose host genus, Eucalyptus. Key words: Apiomorpha, cytogenetics, chromosomal evolution, holocentric.

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