scholarly journals Chromosome synapsis, recombination and epigenetic modification in rams heterozygous for metacentric chromosome 3 of the domestic sheep Ovis aries and acrocentric homologs of the argali Ovis ammon

2019 ◽  
Vol 23 (3) ◽  
pp. 355-361
Author(s):  
T. I. Bikchurina ◽  
E. K. Tomgorova ◽  
A. A. Torgasheva ◽  
V. A. Bagirov ◽  
N. A. Volkova ◽  
...  
Keyword(s):  
Epigenetic Modification ◽  
Centric Fusion ◽  
Domestic Animal ◽  
Ovis Aries ◽  
Metacentric Chromosome ◽  
Farm Animals ◽  
Chromosome 3 ◽  
Domestic Sheep ◽  
Acrocentric Chromosomes ◽  
Nonhomologous Synapsis

Hybridization of domestic animal breeds with their wild relatives is a promising method for increasing the genetic diversity of farm animals. Resource populations derived from the hybridization of various breeds of domestic sheep with mouflon and argali are an important source of breeding material. The karyotypes of argali and domestic sheep differ for a Robertsonian translocation, which occurred in the common ancestor of mouflon and domestic sheep (Ovis aries) due to the centric fusion of chromosomes 5 and 11 of the argali (O. ammon) into chromosome 3 of sheep. It is known that heterozygosity for translocation can lead to synapsis, recombination and chromosome segregation abnormalities in meiosis. Meiosis in the heterozygotes for translocation that distinguishes the karyotypes of sheep and argali has not yet been studied. We examined synapsis, recombination, and epigenetic modification of chromosomes involved in this rearrangement in heterozygous rams using immunolocalization of key proteins of meiosis. In the majority of cells, we observed complete synapsis between the sheep metacentric chromosome and two argali acrocentric chromosomes with the formation of a trivalent. In a small proportion of cells at the early pachytene stage we observed delayed synapsis in pericentromeric regions of the trivalent. Unpaired sites were subjected to epigenetic modification, namely histone H2A.X phosphorylation. However, by the end of the pachytene, these abnormalities had been completely eliminated. Asynapsis was replaced by a nonhomologous synapsis between the centromeric regions of the acrocentric chromosomes. By the end of the pachytene, the γH2A.X signal had been preserved only at the XY bivalent and was absent from the trivalent. The translocation trivalent did not differ from the normal bivalents of metacentric chromosomes for the number and distribution of recombination sites as well as for the degree of centromeric and crossover interference. Thus, we found that heterozygosity for the domestic sheep chromosome 3 and argali chromosomes 5 and 11 does not cause significant alterations in key processes of prophase I meiosis and, therefore, should not lead to a decrease in fertility of the offspring from interspecific sheep hybridization.

THREE NEW CHROMOSOMAL TRANSLOCATIONS IN HAWORTHIA

1968 ◽  
Vol 10 (3) ◽  
pp. 487-494 ◽  
Author(s):  
Herbert P. Riley ◽  
S. K. Majumdar
Keyword(s):  
Reciprocal Translocation ◽  
Acrocentric Chromosome ◽  
Centric Fusion ◽  
Metacentric Chromosome ◽  
Chromosomal Translocations ◽  
Short Chromosome ◽  
Acrocentric Chromosomes ◽  
Fusion Type

In one plant of a small-leaved form of Haworthia glauca a centric fusion type of reciprocal translocation was found between two long chromosomes with subterminal centromeres that interchanged to form a long metacentric and a short acrocentric chromosome; the latter is larger than the normal short chromosomes of the complement and consists of the short arms of the two original long chromosomes. In a typical plant of the same species a similar interchange was followed or accompanied by a second interchange between the short translocation chromosomes and a normal short chromosome to form a somewhat intermediate-sized acrocentric and a very short metacentric chromosome. In a plant of H. fulva a long and a short chromosome interchanged to produce two intermediate-sized acrocentric chromosomes. Possible evolutionary implications of these interchanges are discussed.

CONSERVATION OF NUCLEOLUS ORGANIZER REGIONS DURING EVOLUTION IN SHEEP, GOAT, CATTLE AND AOUDAD

1979 ◽  
Vol 21 (1) ◽  
pp. 1-8 ◽  
Author(s):  
L. M. Henderson ◽  
A. N. Bruère
Keyword(s):  
Ribosomal Dna ◽  
Bos Taurus ◽  
Centric Fusion ◽  
Nucleolus Organizer ◽  
Ovis Aries ◽  
Capra Hircus ◽  
Domestic Sheep ◽  
Banding Patterns ◽  
Nucleolus Organizer Regions ◽  
Ammotragus Lervia

There are ten nucleolus organizer regions (NORs) in domestic sheep (Ovis aries L.), cattle (Bos taurus L.), goat (Capra hircus L.) and aoudad (Ammotragus lervia Blyth) and these are located terminally on chromosomes with homologous G-banding patterns. The similarity in number of nucleolus organizer regions in these species may indicate that their ribosomal DNA regions are infrequently involved in exchange events which could lead to different numbers of active nucleolus organizer regions. Other possible explanations of the conservation of number of nucleolus organizer regions in these species are discussed. The homology of NOR location in these species supports the idea that the Bovidae karyotype tends to be fairly stable apart from changes due to centric fusion events.

scholarly journals Molecular Analysis of Nondisjunction in Mice Heterozygous for a Robertsonian Translocation

Genetics ◽  
2002 ◽  
Vol 161 (3) ◽  
pp. 1219-1224
Author(s):  
Lara A Underkoffler ◽  
Laura E Mitchell ◽  
A Russell Localio ◽  
Shannon M Marchegiani ◽  
Justin Morabito ◽  
...  
Keyword(s):  
Molecular Analysis ◽  
Robertsonian Translocation ◽  
Metacentric Chromosome ◽  
Paternal Age ◽  
Chromosome 7 ◽  
Parental Origin ◽  
Molecular Genotyping ◽  
Factors Influencing ◽  
Meiotic Nondisjunction ◽  
Acrocentric Chromosomes

Abstract A Robertsonian translocation results in a metacentric chromosome produced by the fusion of two acrocentric chromosomes. Rb heterozygous mice frequently generate aneuploid gametes and embryos, providing a good model for studying meiotic nondisjunction. We intercrossed mice heterozygous for a (7.18) Robertsonian translocation and performed molecular genotyping of 1812 embryos from 364 litters with known parental origin, strain, and age. Nondisjunction events were scored and factors influencing the frequency of nondisjunction involving chromosomes 7 and 18 were examined. We concluded the following: The frequency of nondisjunction among 1784 embryos (3568 meioses) was 15.9%.Nondisjunction events were distributed nonrandomly among progeny. This was inferred from the distribution of the frequency of trisomics and uniparental disomics (UPDs) among all litters.There was no evidence to show an effect of maternal or paternal age on the frequency of nondisjunction.Strain background did not play an appreciable role in nondisjunction frequency.The frequency of nondisjunction for chromosome 18 was significantly higher than that for chromosome 7 in males.The frequency of nondisjunction for chromosome 7 was significantly higher in females than in males. These results show that molecular genotyping provides a valuable tool for understanding factors influencing meiotic nondisjunction in mammals.

​Re-sequencing of Whole Genome Jordanian Awassi Ewes using Hiseq Sequencing Technology: Major Step Towards Sheep Genomic Selection

2021 ◽  
Author(s):  
Hussein Migdadi ◽  
Nizar Haddad ◽  
Ruba AlOmari ◽  
Mohammad Brake ◽  
Mustafa AlShdaifat ◽  
...  
Keyword(s):  
Production Systems ◽  
Ovis Aries ◽  
Domestic Sheep ◽  
Major Step ◽  
Illumina Hiseq ◽  
Structure Variation ◽  
Awassi Sheep ◽  
Wide Range ◽  
Number Variation ◽  
Paired End Sequencing

Background: Jordanian Awassi sheep (Ovis aries) is the dominant fat tail sheep breed that appeals to customers because of its various production systems, including fiber, meat and milk. This report is the first whole ewe genome sequence (WGS) of O. aries submitted in the NCBI database from Jordan. Methods: 64 Paired-end sequencing libraries were constructed and subjected to Illumina Hiseq 2500 sequencing system. High-quality reads were aligned against the reference sheep genome and detecting comprehensive sources (SNPs, InDels, SV, CNVs) of genetic variations. We have deposited data sequences at the NCBI under SRA (sequence reads archives) under the accession numbers SRR11128863, PRJNA574879. Result: Genome resequencing of Jordanian Awassi ewe was carried out with approximately 93.88 Gb with a mapping rate and effective mapping depths were 99.28% and 36.32. Around 19 million SNPs, 3,6 million InDels, 35,180 Structure variation and 13,524 copy number variation among the Jordanian ewe genome were detected. This wide range of genetic variation provides a framework for further genetic studies that will help understand the molecular basis underlying phenotypic variation of economically important traits in sheep and improve intrinsic defects in domestic sheep breeds.

Field metabolic rate and water turnover of red kangaroos and sheep in an arid rangeland: an empirically derived dry-sheep-equivalent for kangaroos

2009 ◽  
Vol 57 (1) ◽  
pp. 23 ◽  
Author(s):  
A. J. Munn ◽  
T. J. Dawson ◽  
S. R. McLeod ◽  
D. B. Croft ◽  
M. B. Thompson ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
Grazing Pressure ◽  
Ovis Aries ◽  
Domestic Sheep ◽  
Detailed Knowledge ◽  
Water Turnover ◽  
Field Metabolic Rate ◽  
Red Kangaroo ◽  
Resource Requirements ◽  
Comparative Measure

Sustainable management of pastures requires detailed knowledge of total grazing pressure, but this information is critically lacking in Australia’s rangelands where livestock co-occur with large herbivorous marsupials. We present the first comparative measure of the field metabolic rate (an index of food requirement) of Australia’s largest marsupial, the red kangaroo (Macropus rufus), with that of domestic sheep (Ovis aries; merino breed). We tested the assumption that the grazing pressure of red kangaroos is equivalent to 0.7 sheep, and show this to be a two-fold overestimation of their contribution to total grazing. Moreover, kangaroos had extraordinarily lower rates of water turnover, being only 13% that of sheep. Consequently, our data support arguments that the removal of kangaroos may not markedly improve rangeland capacity for domestic stock. Furthermore, given the low resource requirements of kangaroos, their use in consumptive and non-consumptive enterprises can provide additional benefits for Australia’s rangelands than may occur under traditional rangeland practices.

Description of Diploplastron dehorityi sp. nov. (Entodiniomorphida, Ophryoscolecidae), a new rumen ciliate from Brazilian sheep (Ovis aries)

Zootaxa ◽  
2017 ◽  
Vol 4258 (6) ◽  
pp. 581 ◽  
Author(s):  
FRANCIANE CEDROLA ◽  
ROBERTO JÚNIO PEDROSO DIAS ◽  
ISABEL MARTINELE ◽  
MARTA D’AGOSTO
Keyword(s):  
New Species ◽  
Body Shape ◽  
The Body ◽  
Ovis Aries ◽  
Domestic Sheep ◽  
Diagnostic Features ◽  
Ciliate Community ◽  
The Right ◽  
A New Species

To date the genus Diploplastron comprised only one species of ophryoscolecid ciliate, Diploplastron affine, which is characterized by having two retractable ciliary zones in the anterior end of the body, two slender and juxtaposed skeletal plates on the right side, a rod shape macronucleus, and two contractile vacuoles. During study on the characterization of rumen ciliate community composition in Brazilian domestic sheep, we observed ciliates with atypical morphology but with diagnostic features of genus Diploplastron. This study describes Diploplastron dehorityi, a new species of ophryoscolecid ciliate, that differs from D. affine, primarily, in the morphology of skeletal plates, morphology of nuclear apparatus and body shape. In addition to the similarities between the new species and congener species, D. dehorityi has some morphological similarities to species of genus Eremoplastron.

scholarly journals Differences in leukocyte differentiation molecule abundances on domestic sheep (Ovis aries) and bighorn sheep (Ovis canadensis) neutrophils identified by flow cytometry

2016 ◽  
Vol 46 ◽  
pp. 40-46 ◽  
Author(s):  
Margaret A. Highland ◽  
David A. Schneider ◽  
Stephen N. White ◽  
Sally A. Madsen-Bouterse ◽  
Donald P. Knowles ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Ovis Aries ◽  
Domestic Sheep

scholarly journals Comparison of Passively Transferred Antibodies in Bighorn and Domestic Lambs Reveals One Factor in Differential Susceptibility of These Species to Mannheimia haemolytica-Induced Pneumonia

2011 ◽  
Vol 18 (7) ◽  
pp. 1133-1138 ◽  
Author(s):  
Caroline N. Herndon ◽  
Sudarvili Shanthalingam ◽  
Donald P. Knowles ◽  
Douglas R. Call ◽  
Subramaniam Srikumaran
Keyword(s):  
Differential Susceptibility ◽  
Critical Factor ◽  
Surface Antigens ◽  
Ovis Canadensis ◽  
Ovis Aries ◽  
Mannheimia Haemolytica ◽  
Domestic Sheep ◽  
Experimental Conditions ◽  
Content Type ◽  
Impaired Ability

ABSTRACTMannheimia haemolyticaconsistently causes fatal bronchopneumonia in bighorn sheep (BHS;Ovis canadensis) under natural and experimental conditions. Leukotoxin is the primary virulence factor of this organism. BHS are more susceptible to developing fatal pneumonia than the related speciesOvis aries(domestic sheep [DS]). In BHS herds affected by pneumonia, lamb recruitment is severely impaired for years subsequent to an outbreak. We hypothesized that a lack of maternally derived antibodies (Abs) againstM. haemolyticaprovides an immunologic basis for enhanced susceptibility of BH lambs to population-limiting pneumonia. Therefore, the objective of this study was to determine the titers of Abs directed againstM. haemolyticain the sera of BH and domestic lambs at birth through 12 weeks of age. Results revealed that BH lambs had approximately 18-fold lower titers of Ab against surface antigens ofM. haemolyticaand approximately 20-fold lower titers of leukotoxin-neutralizing Abs than domestic lambs. The titers of leukotoxin-neutralizing Abs in the serum and colostrum samples of BH ewes were approximately 157- and 50-fold lower than those for domestic ewes, respectively. Comparatively, the higher titers of parainfluenza 3 virus-neutralizing Abs in the BH lambs ruled out the possibility that these BHS had an impaired ability to passively transfer Abs to their lambs. These results suggest that lower levels of leukotoxin-neutralizing Abs in the sera of BH ewes, and resultant low Ab titers in their lambs, may be a critical factor in the poor lamb recruitment in herds affected by pneumonia.

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