Chromosome variations in the plains woodrat: A pericentric inversion involving constitutive heterochromatin

1974 ◽  
Vol 30 (1) ◽  
pp. 90-91 ◽  
Author(s):  
J. T. Mascarello ◽  
J. W. Warner
Keyword(s):  
Pericentric Inversion ◽  
Constitutive Heterochromatin

scholarly journals Chromosome comparison between two species of Phyllostomus (Chiroptera - Phyllostomidae) from Eastern Amazonia, with some phylogenetic insights

2000 ◽  
Vol 23 (3) ◽  
pp. 595-599 ◽  
Author(s):  
Luís R.R. Rodrigues ◽  
Regina M.S. Barros ◽  
Maria de Fátima L. Assis ◽  
Suely A. Marques-Aguiar ◽  
Julio C. Pieczarka ◽  
...  
Keyword(s):  
X Chromosome ◽  
Pericentric Inversion ◽  
Constitutive Heterochromatin ◽  
Distal Region ◽  
C Banding ◽  
Primitive Condition ◽  
Autosome Pair ◽  
Phyllostomus Discolor

The karyotypes of Phyllostomus discolor and P. hastatus from Eastern Amazonia were studied by G-, C-, G/C sequential and Ag-NOR techniques. Both species presented 2n = 32, with the autosome complement composed of 30 bi-armed in P. discolor and 28 bi-armed plus 1 acrocentric in P. hastatus. In both species, the X chromosome is medium submetacentric while the Y is minute acrocentric. The present study found only one difference between the karyotypes of P. discolor and P. hastatus: the smallest autosome (pair 15) is bi-armed in discolor and acrocentric in hastatus, a result best explained by pericentric inversion. The C-banding revealed constitutive heterochromatin only at the centromeric regions of all chromosomes, with the NOR site located at the distal region of short arm of pair 15, in both species. The taxon P. discolor is considered primitive for genus Phyllostomus and the bi-armed form of pair 15 is the assumed primitive condition which, rearranged by a pericentric inversion originated the acrocentric from found in P. hastatus.

An Electroporetic and Chromosomal Study of the Dasyurid Marsupial Genus Ningaui Archer

1983 ◽  
Vol 31 (3) ◽  
pp. 381 ◽  
Author(s):  
PR Baverstock ◽  
M Adams ◽  
M Archer ◽  
NL Mckenzie ◽  
RA How
Keyword(s):  
X Chromosome ◽  
Western Australia ◽  
Reciprocal Translocation ◽  
Pericentric Inversion ◽  
Constitutive Heterochromatin ◽  
South Australia ◽  
Isozyme Electrophoresis ◽  
The Third ◽  
Genetic Groups ◽  
Karyotypic Diversity

Isozyme electrophoresis of 28 loci was used to characterize 30 specimens of Ningaui from four States of Australia. The specimens fall into three genetic groups, with large differences between groups (21-32% fixed differences) and genetic homogeneity within groups. One group, from the Pilbara of Western Australia, is referable to N. timealeyi; a second group, extending from the Kalgoorlie area of Western Australia to the far west of South Australia and north to the Tanami Desert of the Northern Temtory, is referable to N. ridei; and a third group extends from the Kalgoorlie area of Western Australia (where it is sympatric with N. ridei) across southern South Australia and into north-westem Victoria. Because the third group maintains its genetic uniqueness despite being sympatric with N. ridei, it clearly represents a different species, N. yvonnae Kitchener, Stoddart & Henry. This species is distinguishable from N. ridei on skull characters, but indistinguishable on external characters. In contrast to most dasyurids, ningauis display considerable karyotypic diversity involving a pericentric inversion, a reciprocal translocation and addition of constitutive heterochromatin to the X-chromosome.

scholarly journals Chromosomal differentiation between the jackrabbits Lepus insularism y Lepus californicus from Baja California Sur, México.

1999 ◽  
Vol 4 (1) ◽  
pp. 40
Author(s):  
Fernando A. Cervantes ◽  
Alejandro Rojas Viloria ◽  
Consuelo Lorenzo ◽  
Sergio Ticul Álvarez Castañeda
Keyword(s):  
Pericentric Inversion ◽  
Baja California ◽  
Constitutive Heterochromatin ◽  
Baja California Sur ◽  
Chromosome Variation ◽  
Banding Patterns ◽  
Interspecific Differences ◽  
Telocentric Chromosomes ◽  
Chromosomal Differentiation ◽  
Lepus Californicus

Resumen: Se estudiaron y compararon los cromosomas de dos especies de liebres de México. Los números diploides y fundamentales de L. insularis fueron 48 y 80, respectivamente, mientras que los de L. californicus fueron 48 and 82. Los autosomas de L. insularis fueron cuatro pares de metacéntricos, cuatro pares de submetacéntricos, nueve pares de subtelocéntricos y seis pares de telocéntricos. En contraste, L. californicus tuvo siete pares de metacéntricos, cuatro pares de submetacéntricos, siete pares de subtelocéntricos y cinco pares de telocéntricos. El cromosoma sexual X de L. insularis fue submetacéntrico de tamaño medio y el cromosoma sexual Y fue telocéntrico y pequeño. Los dos cromosomas sexuales de L.californicus fueron submetacéntricos y medianos. Se identificaron una inversión pericéntrica y dos delecciones en los cromosomas de L. californicus, las cuales explican las diferencias entre los patrones de bandas G de ambas especies. Sus diferencias en heterocromatina constitutiva fueron pocas. Estas diferencias cromosómicas pudieron haber aparecido en una población ancestral aislada de L. californicus durante el Pleistoceno y derivaron en el cariotipo actual de L. insularis. Los resultados complementan conclusiones de estudios morfológicos y morfométricos.Abstract: We evaluated and compared the chromosomes of two species of Mexican jackrabbits. The 2n and FN of L. insularis were 48 and 80, respectively, whereas those of L. californicus were 48 and 82. The autosome morphology of L. insularis is four pairs of metacentric chromosomes, four pairs of submetacentric chromosomes, nine pairs of subtelocentric chromosomes and six pairs of telocentric chromosomes. In contrast, L. californicus had seven pairs of metacentric chromosomes, four pairs of submetacentric chromosomes, seven pairs of subtelocentric chromosomes, and five pairs of telocentric chromosomes. The X chromosome of L. insularis was medium-sized and submetacentric; the Y chromosome was small and telocentric, whereas both sex chromosomes of L. californicus were medium-sized and submetacentric. A pericentric inversion and two deletions in chromosomes of L. californicus were identified which explain the differences between the G-banding patterns of the two species of jackrabbits. There were few interspecific differences within the amount of constitutive heterochromatin. The chromosome variation may have arisen in the isolated ancestor of L. californicus, and produced the karyotype of the extant L. insularis during the Pleistocene. These results complement conclusions from morphological and morphometric comparisons.Key words: Chromosomes, G- bands, C- bands, jackrabbits, Lepus insularis, Lepus californicus, Baja California, México. 

Sex determination and Y chromosome constitutive heterochromatin

2019 ◽  
Vol 1 (1) ◽  
pp. 1-5
Author(s):  
Abyt Ibraimov
Keyword(s):  
Sex Determination ◽  
Y Chromosome ◽  
Constitutive Heterochromatin ◽  
Sex Differentiation ◽  
Secondary Sexual Characteristics ◽  
Biological Meaning ◽  
Heterochromatin Block ◽  
Sexual Characteristics ◽  
Open Question ◽  
Efficient Elimination

In many animals, including us, the genetic sex is determined at fertilization by sex chromosomes. Seemingly, the sex determination (SD) in human and animals is determined by the amount of constitutive heterochromatin on Y chromosome via cell thermoregulation. It is assumed the medulla and cortex tissue cells in the undifferentiated embryonic gonads (UEG) differ in vulnerability to the increase of the intracellular temperature. If the amount of the Y chromosome constitutive heterochromatin is enough for efficient elimination of heat difference between the nucleus and cytoplasm in rapidly growing UEG cells the medulla tissue survives. Otherwise it doomed to degeneration and a cortex tissue will remain in the UEG. Regardless of whether our assumption is true or not, it remains an open question why on Y chromosome there is a large constitutive heterochromatin block? What is its biological meaning? Does it relate to sex determination, sex differentiation and development of secondary sexual characteristics? If so, what is its mechanism: chemical or physical? There is no scientifically sound answer to these questions.

Structure and variability of nucleolar organizer regions in Parodontidae fish

1984 ◽  
Vol 26 (5) ◽  
pp. 564-568 ◽  
Author(s):  
Orlando Moreira-Filho ◽  
Luiz Antonio Carlos Bertollo ◽  
Pedro Manoel Galetti Jr.
Keyword(s):  
Chromosome Pair ◽  
Constitutive Heterochromatin ◽  
Nucleolar Organizer ◽  
Nucleolar Organizer Regions ◽  
Mitotic Chromosomes ◽  
Homozygous Condition ◽  
Nucleolar Organizing Regions ◽  
Nucleolar Chromosome

Nucleolar organizer regions (NORs) were studied in mitotic chromosomes of four species of fish of family Parodontidae: Parodon tortuosus, Apareiodon affinis, Apareiodon ibitiensis, and Apareiodon piracicabae. All four species exhibited only a single nucleolar chromosome pair in their karyotypes. Intraspecific differences were observed in the size of these chromosomes; however, these were not very clear for A. affinis and A. piracicabae, Apareiodon piracicabae exhibited two clearly visible NORs in each of the nucleolar chromosomes, which was the only configuration practically found in this species. This trait therefore predominates in a homozygous condition in the population investigated. Regions of constitutive heterochromatin adjacent to the two NORs were detected. Possible mechanisms that may have originated the two NORs are discussed.Key words: nucleolar organizing regions, fish.

scholarly journals Fertility problems in males carrying an inversion of chromosome 10

Open Medicine ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. 316-321
Author(s):  
Xinyue Zhang ◽  
Qingyang Shi ◽  
Yanhong Liu ◽  
Yuting Jiang ◽  
Xiao Yang ◽  
...  
Keyword(s):  
Spontaneous Abortion ◽  
Pericentric Inversion ◽  
Paracentric Inversion ◽  
Chromosome 10 ◽  
Partial Duplication ◽  
Recurrent Miscarriages ◽  
First Case ◽  
Fertility Problems ◽  
Male Carriers ◽  
Male Carrier

Abstract Chromosomal inversion is closely related to male infertility. Inversion carriers may produce abnormal gametes, which may lead to partial duplication/deletion of the embryonic chromosome and result in spontaneous abortion, a fetus with multiple anomalies, or birth of a malformed child. Genetic counselling remains challenging for these carriers in clinical practice. We report two male carriers with inversion of chromosome 10 and review 26 reported cases. In the first case, 46,XX,inv(10)(p13q22) of the fetal chromosome was found in prenatal diagnosis; this was inherited from the paternal side with 46XY,inv(10)(p13q22). Another case was a male carrier with inv(10)(q21.2q22.1). There have been 25 (89.3%) cases of pericentric inversion and three (10.7%) cases of paracentric inversion involving chromosome 10. Of 28 cases, nine were associated with pregestational infertility of the couples, while the other 19 cases were associated with gestational infertility of the couples or normozoospermia. The breakpoints at 10p15, 10p11, 10q11, and 10q21 were associated with pregestational infertility of the couples. The breakpoints at 10p15, 10p14, 10p13, 10p12, 10p11, 10q11, 10q21, 10q22, 10q23, 10q24, 10q25, and 10q26 were related to gestational infertility of the couples or normozoospermia. Although there is a high risk of infertility or recurrent miscarriages, carriers with inversion of chromosome 10 might produce healthy offspring. Natural pregnancy can be used as a choice for inversion carriers with recurrent spontaneous abortion.

Prenatal Diagnosis in Pericentric Inversion 6

2010 ◽  
Vol 10 (1-3) ◽  
pp. 175-178 ◽  
Author(s):  
J. Gazala ◽  
I. V. Amithkumar ◽  
J. Sabina ◽  
K.K. Praveena ◽  
J. Sujatha
Keyword(s):  
Prenatal Diagnosis ◽  
Pericentric Inversion
Sign in / Sign up

Export Citation Format

Share Document