Although the physiological role of relaxin (RLN) in males remains largely unknown, there is limited evidence that the testis might be a candidate source and target of RLN in boars, as RLN transcripts are detected in the boar testis and it contains RLN-binding sites. To determine whether the boar testis acts as a source and target tissue of RLN, we characterised the expression pattern and cellular localisation of both RLN and its own receptor LGR7 (RXFP1) in boar testes during postnatal development by molecular and immunological approaches. Testes were collected from Duroc boars, and partial cDNA sequences of the boar homologue of human RXFP1 were identified. RLN expression increased through puberty onwards, while RXFP1 expression changed little during development.RLN mRNA and protein expression were restricted to the Leydig cells, whereas both Leydig cells and seminiferous epithelial cells expressed RXFP1 mRNA and protein.Interestingly, RLN was expressed in the testis as an 18 kDa form (the expected size of proRLN), but not as the 6 kDa mature form, during development because of a lack of the enzyme required for proRLN processing. In contrast, RXFP1 was detected at all stages as specific bands of 75 and 91-95 kDa (likely non-glycosylated and glycosylated RXFP1 respectively). Thus, we provide evidence for expression of RLN-RXFP1 ligand-receptor system in the boar testis, suggesting that the testis act as a source and possible target tissue of RLN.

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Relaxin-like factor (RLF), also called insulin-like peptide 3 (INSL3), is a member of the insulin/relaxin gene family and is produced by testicular Leydig cells. While the understanding of its effects is accumulating, very little is known about the structural and functional properties of native INSL3. Here, we demonstrate that native INSL3 isolated from goat testes is a single-chain structure with full biological activity, and is constitutively expressed and secreted by Leydig cells. Using a series of chromatography steps, native INSL3 was highly purified as a single 12-kDa peak as revealed by SDS-PAGE. MS/MS analysis provided 72% sequence coverage and revealed a distinct single-chain structure consisting of the B-, C-, and A-domains deduced previously from the INSL3 cDNA sequence. Moreover, the N-terminal peptide was 6 amino acid residues longer than predicted. Native INSL3 exhibited full bioactivity in HEK-293 cells expressing the receptor for INSL3. Immunoelectron microscopy and Western blot analysis revealed that INSL3 was secreted by Leydig cells through the constitutive pathway into blood and body fluids. We conclude, therefore, that goat INSL3 is constitutively secreted from Leydig cells as a B-C-A single-chain structure with full biological activity.

Relaxin-like factor (RLF), also called insulin-like peptide 3 (INSL3), is a member of the insulin/relaxin gene family and is produced by testicular Leydig cells. While the understanding of its effects is growing, very little is known about the structural and functional properties of native INSL3. Here, we demonstrate that native INSL3 isolated from goat testes is a single-chain structure with full biological activity, and is constitutively expressed and secreted by Leydig cells. Using a series of chromatography steps, native INSL3 was highly purified as a single 12-kDa peak as revealed by SDS-PAGE. MS/MS analysis provided 81% sequence coverage and revealed a distinct single-chain structure consisting of the B-, C-, and A-domains deduced previously from the INSL3 cDNA sequence. Moreover, the N-terminal peptide was six amino acid residues longer than predicted. Native INSL3 exhibited full bioactivity in HEK-293 cells expressing the receptor for INSL3. Immunoelectron microscopy and Western blot analysis revealed that INSL3 was secreted by Leydig cells through the constitutive pathway into blood and body fluids. We conclude, therefore, that goat INSL3 is constitutively secreted from Leydig cells as a B-C-A single-chain structure with full biological activity.

Relaxin-like factor (RLF), also known as insulin-like factor 3 (INSL3), is produced by testicular Leydig cells, but its specific receptor LGR8 (leucine-rich repeat family of G-protein-coupled receptor 8) has not been identified in goats. This study aimed to identify complementary DNA (cDNA) sequences of goat LGR8, and characterize the expression of both RLF and LGR8 in goat testes by RT-PCR and immunohistochemistry. Testes were collected from immature (3-month-old) and mature (24-month-old) Saanen goats, and partial cDNA sequences of the goat homologue of human LGR8 were identified. The sequence encoded a reduced peptide sequence of 167 amino acids, which corresponded to transmembrane regions 2 through 5, followed by the beginning of intracellular loop 3 of human LGR8. Expression of both LGR8 and RLF genes was drastically increased in mature testes compared with immature ones. Although RLF protein was restricted to Leydig cells, LGR8 protein was detected in both Leydig cells and seminiferous epithelial cells (possibly germ cells and Sertoli cells). These results reveal a possible existence of the RLF-LGR8 ligand-receptor system within the goat testis, suggesting that RLF may play a role in testicular function through LGR8 on Leydig cells and seminiferous epithelial cells in an autocrine and/or paracrine manner.

Insulin-like factor 3 (INSL3), previously called relaxin-like factor (RLF), is essential for testis descent during fetal development and has been implicated in the testicular and sperm functions in adult males. However, similar functions in ruminants remain largely unknown. This chapter will cover recent advancement in our understanding of INSL3 in goats. First, testicular Leydig cells were the sole source of INSL3, with INSL3 expression increasing during development. Second, INSL3 was constitutively secreted as a B-C-A single-chain structure with full biological activity. Third, secreted INSL3 was transported into the seminiferous compartments, where its receptor RXFP2 was expressed on germ cells, thus suggesting that the intratesticular INSL3 hormone-receptor system operates in germ cells. Fourth, functional RXFP2 enabling INSL3 to bind was also identified in the spermatozoa and suggested the existence of the extratesticular INSL3 hormone-receptor system in the spermatozoa. Interestingly, percentages of INSL3-binding spermatozoa were significantly reduced in the semen of subfertile bulls compared to that of fertile bulls, suggesting the potential of this system to diagnose fertility in breeding sires. These fascinating findings will give a new perspective in physiological and/or therapeutic actions of INSL3 on male reproductive processes in domestic ruminants, including goats.

Commercial banks play an important role in the Mongolian financial system. Although Mongolian commercial banks have shown great development in the past two years, the low efficiency of the banking industry is still a problem that has plagued Mongolia's financial industry in a period of time. Therefore, improving the efficiency of commercial banks is the key to the sustainable development of Mongolia's financial industry problem. In order to analyze the operational efficiency of Mongolian commercial banks, this paper is based on the DEA-Malmquist index analysis method for the first time to study the total factor productivity of 13 Mongolian commercial banks in 2013-2017. The results show that: (1) the total factor productivity of Mongolian commercial banks is generally on the rise; (2) the changes in pure efficiency and pure technology are generally on the rise; (3) the changes in the scale factors of Mongolian commercial banks show two trends.