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Steroidogenic factor-1 (SF-1) and liver receptor homolog-1 (LRH-1) belong to the nuclear receptor superfamily and are categorized as orphan receptors. In addition to other nuclear receptors, these play roles in various physiological phenomena by regulating the transcription of target genes. Both factors share very similar structures and exhibit common functions. Of these, the roles of SF-1 and LRH-1 in steroidogenesis are the most important, especially that of SF-1, which was originally discovered and named to reflect such roles. SF-1 and LRH-1 are essential for steroid hormone production in gonads and adrenal glands through the regulation of various steroidogenesis-related genes. As SF-1 is also necessary for the development of gonads and adrenal glands, it is also considered a master regulator of steroidogenesis. Recent studies have clearly demonstrated that LRH-1 also represents another master regulator of steroidogenesis, which similarly to SF-1, can induce differentiation of non-steroidogenic stem cells into steroidogenic cells. Here, we review the functions of both factors in these steroidogenesis-related phenomena. [ABSTRACT FROM AUTHOR]

The article presents a 2013 case study that aims to identify differences in stress measures in pigs with the roles of a tail biter, a victim, a control in the same pen, and one in a pen without tail biting, during a tail-biting outbreak. Stress measures used include behavior, thyroid hormone concentration and adrenal and thyroid gland morphology. The study shows that neutral pigs represent a phenotype with a coping strategy for lowering stress levels in comparison with tail biters and victims.