Summer diet of domestic sheep and saiga in the Caspian lowland pastures

Abstract The last decade has seen a dramatic increase in the number of livestock QTL mapping studies. The next challenge awaiting livestock geneticists is to determine the actual genes responsible for variation of economically important traits. With the advent of high density single nucleotide polymorphism (SNP) maps, it may be possible to fine map genes by exploiting linkage disequilibrium between genes of interest and adjacent markers. However, the extent of linkage disequilibrium (LD) is generally unknown for livestock populations. In this article microsatellite genotype data are used to assess the extent of LD in two populations of domestic sheep. High levels of LD were found to extend for tens of centimorgans and declined as a function of marker distance. However, LD was also frequently observed between unlinked markers. The prospects for LD mapping in livestock appear encouraging provided that type I error can be minimized. Properties of the multiallelic LD coefficient D′ were also explored. D′ was found to be significantly related to marker heterozygosity, although the relationship did not appear to unduly influence the overall conclusions. Of potentially greater concern was the observation that D′ may be skewed when rare alleles are present. It is recommended that the statistical significance of LD is used in conjunction with coefficients such as D′ to determine the true extent of LD.

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Pedosedimentary environments in the Caspian Lowland during MIS5 (Srednaya Akhtuba reference section, Russia)

Quaternary International ◽

10.1016/j.quaint.2021.03.015 ◽

2021 ◽

Author(s):

Alexander Makeev ◽

Marina Lebedeva ◽

Alexandra Kaganova ◽

Alexey Rusakov ◽

Pavel Kust ◽

...

Keyword(s):

Caspian Lowland ◽

Reference Section

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Standard G-, Q-, and R-banded ideograms of the domestic sheep (Ovis aries): homology with cattle (Bos taurus). Report of the committee for the standardization of the sheep karyotype

Cytogenetic and Genome Research ◽

10.1159/000015286 ◽

1999 ◽

Vol 85 (3-4) ◽

pp. 317-324 ◽

Cited By ~ 9

Author(s):

H.A. Ansari ◽

A.A. Bosma ◽

T.E. Broad ◽

T.D. Bunch ◽

S.E. Long ◽

...

Keyword(s):

Bos Taurus ◽

Ovis Aries ◽

Domestic Sheep

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AROMATIZING ACTIVITY OF PLACENTAL MICROSOMAL FRACTIONS FROM EWES IN LATE GESTATION

Journal of Endocrinology ◽

10.1677/joe.0.0650117 ◽

1975 ◽

Vol 65 (1) ◽

pp. 117-125 ◽

Cited By ~ 10

Author(s):

M. R. MANN ◽

L. B. CURET ◽

A. E. COLAS

Keyword(s):

Sharp Increase ◽

Enzyme System ◽

Hydroxysteroid Dehydrogenase ◽

Relative Increase ◽

Late Gestation ◽

Domestic Sheep ◽

Dramatic Rise ◽

Oestradiol Production ◽

Human Placentae

SUMMARY Placental microsomes from eight domestic sheep at 136–146 days of gestation were incubated with radioactive androstenedione, testosterone and dehydroepiandrosterone. Aromatizing activity was examined in the presence and absence of cortisol and the rates of both oestrone and oestradiol synthesis were measured. Oestrone predominated in preference to oestradiol in most of the incubations, a result opposite to that found with human placentae. The sharp increase in the rate of oestradiol production found in the 144- to 146-day-old placentae incubated with testosterone may indicate a more rapid increase of aromatizing than of 17β-hydroxysteroid dehydrogenase activity. The presence of cortisol in the mixtures did not significantly affect the placental aromatizing activity, indicating that there is no direct effect of cortisol on the enzyme system as measured in vitro. The dramatic rise of overall mean aromatizing activity from 4·86 ± 0·22 (s.e.m.) at 138–141 days of gestation to 12·96 ± 0·38 pmol/mg protein/min at 144–146 days (with a greater relative increase in the rate of oestradiol formation), suggests that changes in placental aromatizing activity may play an important role in maternal and foetal plasma oestrogen surges before ovine parturition.

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The Origins of Domestic Sheep and Goats: a Reconsideration in the Light of the Fossil Evidence

Proceedings of the Prehistoric Society ◽

10.1017/s0079497x00013943 ◽

1969 ◽

Vol 34 ◽

pp. 368-384 ◽

Cited By ~ 8

Author(s):

Sebastian Payne

Keyword(s):

Direct Evidence ◽

Present Situation ◽

Wild Relatives ◽

The Other ◽

Domestic Sheep ◽

Sheep And Goats ◽

Animal Domestication ◽

The Past ◽

The One ◽

And Control

In recent discussions of the origins and process of animal domestication (Reed, 1961, Zeuner, 1963), both authors rely on two kinds of evidence: on the one hand, the present distributions and characteristics of the different breeds of whatever animal is being discussed, together with its feral and wild relatives, and, on the other hand, the past record, given by literary and pictorial sources and the bones from archaeological and geological sites. Increased recognition of the limitations of the past record, whether in the accuracy of the information it appears to give (as in the case of pictorial sources), or in the certainty of the deductions we are at present capable of drawing from it (this applies especially to the osteological record), has led these authors to argue mainly from the present situation, using the past record to confirm or amplify the existing picture.Arguing from the present, many hypotheses about the origins and process of domestication are available. The only test we have, when attempting to choose between these, lies in the direct evidence of the past record. The past record, it is freely admitted, is very fragmentary: the information provided by the present situation is more exact, ranges over a much wider field, and is more open to test and control. Nevertheless, the past record, however imperfect it is, is the only direct evidence we have about the process of domestication.

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