Maintenance of horse embryonic stem cells in different conditions

Embryonic stem cells [EScs] are originally derived from the ICM of blastocysts and are characterized by their ability to self-renew and their pluripotencies. Only a few reports have been published on ESC isolations and line establishment in animals, even fewer in horses. However, it is still important to isolate equine ESCs for animal biotechnology and therapeutic applications. In the present study, we tried to derive horse ESC lines from the ICM of blastocysts fertilized in vivo and maintain their pluripotencies in different conditions. The primary horse ESCs were able to self-renew when they were cultured in basic medium on gamma-irradiated colonies were positive for Oct-4, SSEA-1, GCTM-2, TRA-1-60 and TRA-1-81. Moreover, to optimize the culture conditions, these putative horse ESCs were cultured in basic medium supplemented with human leukemia inhibitory factor [hLIF] only, human basic fibroblastic growth factor [hbFGF] only, or hbFGF plus hLIF with or without heterologous [MEF] feeder cells. Based on our results, the heterologous feeder [MEF] cells are necessary to maintain the undifferentiated state for horse ESCs, and ESC-like cell morphology of suggested that hLIF was neither prerequisite nor negative for maintenance of horse ESCs; bFGF seemed to be negative for maintenance of horse ECSs and the combination of hLIF and bFGF was unable to improve the culture condition

[Detection of leptin and leptin receptor mRNA expression in the bovine testis]

Leptin, hormonal product of the ob gene, is known to regulate food intake, energy metabolism and reproductive functions in mammals. The mechanism by which leptin affect male reproductive system, in contrast to its well proven effects in female fertility, has been a matter of debate. Expression of leptin and its receptor in some reproductive organs suggest that leptin has both endocrine and paracrine/autocrine effects on reproduction. Various evidences have pointed to a direct role of leptin in the control of rodent testicular function such as steroidogenesis and spermatogenesis. So, detection of leptin and leptin receptor mRNA in bovine testis will be the first crucial step to an understanding of its paracrine/autocrine effect on testes in cattle. In the present study, we showed the expression of leptin mRNA as well as its functional receptor [Ob-Rb] mRNA in whole testis of Holstein cattle using reverse transcription and polymerase chain reaction [RT-PCR] analysis. To confirm the first results, RT-PCR products were amplified with Nested PCR using inner leptin primer pairs designed on different exons. Based on our results, although we could not determine the exact cell source of leptin in / testis, it suggests that besides its primary actions at the hypothalamic-pituitary level, leptin can also involved in autocrine and/or paracrine mechanisms in testicular physiology in cattle

Color discrimination in Caspian pony

Although an early and influential review led to the often-cited conclusion that color vision is rare among mammals, more recent findings suggest that it is actually widespread. According to Jacobs, all non-nocturnal mammalian species that have been adequately examined show some color vision capacity, although the degree varies enormously. Data on the presence and characteristics of color vision in the horse, however, remain sparse and none in the case of ponies. Eight Caspian ponies were presented with a series of two-choice color vs. grey discrimination problems. One mare pony was eliminated due to traumatic injury to the eye. Experiments were performed in a box of 3 _ 3 meter containing a wall with two translucent panels that were illuminated from behind by light projected through color or grey filters to provide the discriminative stimuli. Ponies were first adopted to the stall [box] with two panels in it and then learned to push one of the panels in order to receive the food rewards behind the positive stimuli in an achromatic light-dark discrimination task. The ponies were then tested on their ability to discriminate between grey and four individual colors: red; 617 nm., yellow; 581 nm., green; 538 nm. and blue; 470 nm. The criterion for learning was set at 85% correct response, and final testing for all color vs. grey discrimination involved grey of varying intensities, making brightness an irrelevant cue. The ponies were tested with all four colors vs. grey discriminations. Except two ponies, the rest were successfully reached the criterion for learning blue color vs. grey discrimination. Only two ponies reached the criterion for learning green color vs. grey discrimination. Only tow ponies reached the criterion for discriminating red and yellow vs. grey. So the answer to the question "do the ponies see color" is yes, they can discriminate between the four selected color vs. grey