Histomorphological perspectives of preputial and clitoral glands of soft-furred field rat Millardia meltada

Abstract

The present study was an attempt to understand the sexual dimor-phism of the integumentary scent glands of soft-furred field rat Millardia meltada from the perspectives of anatomy, morphology and histology with view to correlate with the sex-specific pheromones they produce. The scent gland of male is known as preputial gland, and female, the clitoral gland. The rats, that are agricultural pests were field caught, the glands of males and females of almost identical size were dissected out, and subjected to gravimetric, morphometric and histological analyses. Both glands are yellowish-brown, pear-shaped, and dorsoventrally compressed. The mean weight, length and width of preputial glands are significantly (p < 0.05) larger than that of the clitoral glands. The preputial gland is composed of sebaceous glandular lobules and apocrine glandular lobules whereas the clitoral gland is formed only of sebaceous glandular lobules. The sebaceous glandular lobules of both preputial and clitoral glands are filled with a wax-like material. Thus, the scent glands of the soft-furred male field rats exhibit sexual dimorphism in respect histoarchitecture of the glands and the nature of the secretory material. This sexual dimorphism of the scent glands may reflect control by male and female sex hormones impinging on specific roles as sex attractant pheromones.

Histomorphology and Chemical Constituents of Interdigital Gland of Vembur Sheep, Ovis aries

“…Moreover, males have higher values for interdigital gland weight, length, and width than females. These findings are in agreement with those reported by Abbasi et al [6] in Iranian sheep, Rajagopal and Archunan [34] in Indian Blackbuck, Awaad et al [35] in Egyptian sheep, Yilmaz et al [33] in Awassi sheep, Ponmanickam et al [36] in the Bandicoot rat, Kara et al [18] in Hasmer and Hasak sheep, and Rajagopal et al [37] in the soft-furred field rat, etc. In another context, the dominant male (adult) blackbucks have larger preorbital glands and higher testosterone levels than subordinate males (sub-adults and adolescents) [34,38].…”

“…Similar observations have been made on the interdigital gland of various other species, including the madoqua [42], red duiker [9], Kivircik sheep [32], Awassi sheep [33], Hasak sheep [18], and Konya Merino sheep [19] etc. In contrast, the preputial and clitoral glands of male and female soft-furred field rats show sexual dimorphism, the male having sebaceous and apocrine secretory lobules, whereas the female having apocrine secretory lobules [37]. The infraorbital gland of male Japanese serow has an ordinary sebaceous gland, whereas female has a modified one [43].…”

“…Japanese serow secretes large amounts of glycoconjugates (bound volatiles) through the apocrine portion of the infraorbital gland [46]. It is reported that the pheromone compounds derived mainly from the sebaceous glands, on discharge to the outside, can adhere to objects, and the secretion of apocrine glands promotes stronger adhesion capacity and high persistence in the scented site during the expression of territorial/scent marking [34,37,47]. The present result suggests that the apocrine gland in the interdigital gland of Vembur sheep contributes to the secretion of volatile substances that may be useful for chemical communication between Vembur sheep herds.…”

External genitalia phenotypes of a Mab21l1‐null mouse model for cerebellar, ocular, craniofacial, and genital (COFG) syndrome

“…Morphologically, each PG/CG consists of one hair follicle, glandular primordia, and the surrounding mesenchyme (Cunha, 1975; Figures 1a and 2a, S2A). The glandular epithelia produce the lipid compounds and secrete them through one excretory duct into the preputial surface after sexual maturation (Rajagopal et al, 2020). The gross‐anatomically isolated PG/CG showed a significant atrophy in Mab21l1 −/− pups throughout neonatal to adult stages as compared with wild‐types (Figures 2a,d and S2A–B; Table S1).…”

“…After birth, the PG/CG are rapidly developed, round‐oval in shape, and appear yellowish in color. These glands produce lipid compounds associated with pheromone function in rodents (Liu et al, 2019; Rajagopal et al, 2020). This is in sharp contrast to the poor development of human PG/CG counterparts, which are only scattered modified folliculosebaceous glands on the corona, neck, glans, and inner layer of the prepuce in men, but a complete lack of CG in women (Batistatou et al, 2006; Fernandez‐Flores, 2014; Standring, 2021; Van der Putte & Sie‐Go, 2011).…”