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The recent state of cryopreservation techniques for ex-situ gene conservation and breeding purposes in small ruminants: A review
81-87Views:290The viewpoint of the recent cryopreservation techniques (CT) suggests the use of a reduced volume of cryopreservation solution, high concentration of cryoprotectants and ultra-rapid cooling and warming rates help to reduce cryo-injury and maximize the viability of the preserved animal genetic resources (AnGR). The CT had now become widely accepted as one of the best methods of choice for the ex-situ conservation of AnGR due to its high success rate recorded and no-invasive nature as compared to the conventional slow rate freezing (CSRF). Rapid advances and wide acceptability of the use of assisted reproductive technologies (ART’s) particularly artificial insemination (AI) in animal breeding had resulted in a greater loss of a large number of good quality genes in virtually almost all the native breeds of animals across the globe. Small ruminant (SR) animals are not an exception in such present predicaments situation of erosion and dilution of the valuable AnGR among the native breeds. As a result of this, 148 and 16 breeds of sheep and goats respectively have already become extinct in Europe and the Caucasus. In view of the aforementioned situation, the present review aimed at exploring some of the current states of development, roles played and potentials of CT in the conservation of SR genes and genome for the immediate and future breeding purposes for sustainable development. It basically covers; animal genetic resource, the need to conserve AnGR, tools for ex situ in vitro conservation of AnGR and recent developments in breeding and cryopreservation of SR AnGR.
Cryopreservation is playing a pivotal role in ex-situ gene conservation of AnGR. Decline in genetic diversity among SR breed population was high in Europe and the Caucasus. There is therefore, need for improvent on current stringent measures on conservation of AnGR in this region of the world.
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Investigation of intersexual polled goats
11-15Views:158The sex reversal may occur in all mammalian species, but is connected to a favourable trait – the polledness – only in the goat. Later abnormal sex ratio was noticed in these goat populations, in which a part of the phenotypically male individuals was sterile. These males have two X chromosomes. In goats the PIS (Polled Intersex Syndrome) mutation is responsible for the absence of horns in homozygous and heterozygous individuals. This same mutation causes a female-to-male sex reversal, but only in the homozygous polled genetic female goats. The PIS mutation inhibits the expression of the FOXL2 gene which is responsible for ovary development, and a protein encoded by this gene inhibits the activity of the Sox9 gene. The Sox9 gene stimulates the development of the cells of the testis. When the FOXL2 gene is inhibited, the Sox9 gene is activated and transforms the ovary cells into testis cells. In our article we briefly introduce the morphological and chromosome investigations of three intersex individuals we found.