Differential Development of Sex-related Characters of Chickens from the GSP and PNP/DO Inbred Lines after Left Ovariectomy

Abstract

Abstract. To elucidate strain differences in the sex reversal of genetic females to phenotypic males, GSP and PNP/DO females were left ovariectomized (ovx) between one to three days after hatching, and the degree of masculinization based on sex-related characters, histological analysis of the right gonad and hormone assay were assessed at one year of age. The GSP and PNP/DO inbred lines were both derived from the Fayoumi breed and are only differentiated based on the red blood cell antigen type carried by each inbred line. Combs and wattles were found to be significantly bigger (P<0.05) in the GSP ovx compared with the PNP/DO ovx chickens, although male plumage patterns were more pronounced in the PNP/DO ovx. Spurs were observed both in the GSP and PNP/DO ovx chickens with no significant difference (P>0.05) in length compared with the respective male controls, and body weight was not significantly different (P>0.05) compared with the female controls. The weight of the right gonad was significantly heavier (P<0.05) in the GSP ovx than in the PNP/DO ovx. Positive correlations were found in the sex-related characters as well as the plasma testosterone level and right gonad weight in both the GSP and PNP/DO ovx chickens, but not in the spur length, which showed a negative correlation in the PNP/DO ovx chickens. Histological analysis revealed that the right gonads of the PNP/DO ovx chickens were morphologically developed compared with the GSP ovx chickens, which showed more advance stages of spermatogenesis. It could be inferred that PNP/DO females that exhibit a hereditary persistent right oviduct are more responsive to the masculinizing effect of ovariectomy compared with GSP females, suggesting that genetic background may have a possible contribution to the degree of masculinization and subsequent development of sex related characters.

Identification of an Epigenetically Marked Locus within the Sex Determination Region of Channel Catfish

“…The idh2 loci were tightly linked to the sex determination element in conchostracan shrimp, Eulimnadia texana [ 55 ]. Chd2 is one of the sex chromosome-linked genes used for sex identification in birds [ 56 , 57 ]. Other genes within the SDR of channel catfish functionally related to sex differentiation and gonadal development in other species included a cell adhesion gene, nectin1, which was explicitly upregulated in the sexually differentiating gonads of mice [ 58 ], and E3 ubiquitin-protein ligase trip12 gene, which play a role in chromatin modification of early germ cells in rat testis [ 59 ].…”

Comparison of DNA Isolation and Dominant and Co-dominant Molecular Markers to Reveal the Genetic Sex of Gallus domesticus (Domestic Chickens)

“…Effi cacy of procedures was assessed with diff erent combinations of initial blood, lysis buff er and protein denaturant in relation to the DNA yield and purity. (Valdez et al, 2010) The Journal of Agricultural Sciences -Sri Lanka , 2019, Vol.14, No. 3…”

“…Two known samples from mature male and female were used as reference samples. Three primer sets namely CHD1, HUR0423 and HUR0424 (Maxwell et al, 1987;Valdez et al, 2010) were used for the PCR amplifi cation (Table 02).…”

Genetic Foundation of Male Spur Length and Its Correlation with Female Egg Production in Chickens

“…Spurs are located below the calves on both sides and above the feet, connected to the tarsometatarsus by a bony core, and can grow with age [ 8 ]. Spur length is believed to be related to lighting stress [ 11 ], hormone levels [ 12 , 13 , 14 ], and growth conditions [ 15 ], and may play a certain role in individual viability [ 16 , 17 ], mate choice [ 16 , 18 ], and reproduction [ 16 , 17 ]. In the past, many people thought of the spur as the toe of a chicken, but its diameter was much larger than the toes, which could be considered as the protruding part of the shank.…”