2008 A P P L I E D A N D N A T U R A L S C I E N C E F O U N D A T I O N ANSF JANS Journal of Applied and Natural Science 9 (1): 421– 426 (2017) Prenatal development of the lingual epithelium in goat (Capra hircus) Yousuf Dar * , Kamal Sarma, Shalini Suri and Jonali Devi Division of Veterinary Anatomy, Faculty of Veterinary Sciences, A.H. Sher -e-.Kashmir University of Agricultural Sciences & Technology, Jammu-181102 (J&K), INDIA *Corresponding author. E-mail: yousufdar8@gmail.com Received: May 9, 2016; Revised received: December 12, 2016; Accepted: February 10, 2017 Abstract: The present study was conducted on the tongue of 18 goat foetii divided into three prenatal age groups viz- Group I ( below 50 days of gestation), Group II ( between 50-100 days of gestation) and Group III ( above 100 days of gestation to up to full term) containing 6 number of foetii in each group to study the sequential events in re- gard to histological development of the same in goat foetii. The tongue was lined by 3-4 layered epithelium in the foetus at 40 days of gestation (CRL= 2.40cm). The lingual epithelium consisted of a basal layer of cuboidal cells with squamous to cuboidal shaped more superficial layers. At 62 days of gestation (CRL= 10.10 cm), the lamina epitheli- alis of the tongue of goat foetus was distinctly stratified. At this stage of development, the epithelial layers could be divided into dark basal and a light apical or superficial zones. At 80-84 days of gestation (CRL=15.3 to 16.0 cm), the stratified squamous epithelium of the tongue was better developed both on the dorsum and ventral surfaces. At 93 days of gestation (CRL= 20.6 cm), the stratified squamous epithelium of the tongue was well developed and all the layers of the epithelium could be observed. In the foetii of gestational age of 100 days onwards, the lingual epitheli- um of the tongue showed various degrees of keratinization. Thus, it was concluded that the tongue of goat was lined with 3-4 layers of epithelial cells. The degree of stratification increased with an increase in gestational age. Also with age there was an increase in the degree of keratinization. This research further implicated that with further advance- ment of age the basal layer of the epithelium comprised high cylindrical cells along with well defined basement membrane. The decrepancy of histogenesis and keratogenesis between different species may be due to difference in the duration of the gestation period. Keywords: Goat, Histomorphology, Prenatal development, Tongue, INTRODUCTION The tongue in mammals is an extremely muscular organ within whose substances there are a number of smaller salivary glands and many number of motor and sensory nerve fibres (Sisson and Grossman, 1975; Dyce et al., 1996). The bulk of tongue is skeletal muscle, arranged in three layers all at right angles to each other (Sisson and Grossman, 1975; Reece, 2004) giving it a degree of flexibility for prehension and mastication of food (Getty, 1975; Dyce et al., 1996). Majority of tongue muscles are somatic in origin (Yamane, 2005). The presence of prominent torus linguae with a crescentic depression – fossa linguae was reported in the tongue of ox and sheep (Habel, 1975), goat (Qayyum and Beg, 1975), buffalo (Dhingra and Barnwal, 1979; Prakash and Rao,1980). The torus linguae probably compensates for the deficient masticatory mechanism caused by absence of incisors in the upper jaw (Labh and Mitra, 1969). It has been observed that the morphogenesis and cytodifferentiation in developing vertebrate organs is controlled by the sequential and reciprocal interaction between the epithelial and mesenchymal tissues (Jitpukdeebodintra et al., 2002). Development of ISSN : 0974-9411 (Print), 2231-5209 (Online) All Rights Reserved © Applied and Natural Science Foundation www.jans.ansfoundation.org different papillae occurs prenatally and in a very specific spatial and temporal pattern. Although each type is morphologically distinct, the initial events in the development in all mammals are histologically similar (Mistretta, 1991) and later on there must be progressive differentiation to acquire the papillary epithelial taste progenitor cell and finally taste cell within the papillary apex (Mistretta and Liu, 2006). In the foetus, the tongue begins to form at approximately the same time as the palates. It extends from various protuberances on the pharynx floor. Already at the time of the medial fusion of the first (mandibular) and second (hyoid) pharyngeal arches a medial protuberance, the tuberculum impar, appears on the lower edge of mandibular arch. To the left and right of it two further swellings form, the lateral lingual prominences. These three swellings extend from the mandibular arch and later form the anterior 2/3 of the tongue. The posterior third is formed from the materials of the fusion site of the second and third pharyngeal archs, the copula, and small portion of 4 th pharyngeal arch. The third pharyngeal arch probably grows over the second one so that in the end the second one has no mesenchymal contribution to