Anatomy and Histophysiological Changes in Pituitary of Calotes versicolor During Breeding and Nonbreeding Seasons

Abstract

Calotes versicolor, collected during peak breeding and nonbreeding season were used for the study of anatomy and histophysiology of pituitary gland. In C. versicolor the pituitary gland is small compact mass attached to the hypothalamus by a delicate stalk. It is of two basic units, adenohypophysis and neurohypophysis. The adenohypophysis includes pars distalis (PD) and pars intermedia (PI). The pars tuberalis (PT) which is usually reduced in reptiles, is absent in C. versicolor. The neurohypophysis is composed of median eminence (MI) and neural lobe or pars nervosa (PN). The anterior PD is rich acidophils than the posterior PD during breeding season. These cells are differentiated as A1 and A2 cells. The A1 cells are erythrosinophilic and stained purple or red and A2 cells stained yellow with orange G. The identified A1 cells are regarded as lactophores and A2 cells are regarded as somatotropes. The secretion of these cells and cell number is reduced during nonbreeding season. The basophils of PD are PAS +, AF + and aniline blue + during breeding season. These cells are classified as B1 and B2 cells depending on their size and location. The large B2 cells are present in cords and B1 cells are located closely to these parts. The B1 and B2 cells are regarded as thyrotrophs and gonadotrophs respectively. During nonbreeding these cells show negative response to the above stain. The PI is large and labulated. The cells are AF+, erythrosine and secrete highly granular material during breeding season. During nonbreeding season they become AF-, erythrosine-and less secretory. The secretion present in neurosecretory cells of the neural lobe appears as large granules and they are AF+. These cells take deep blue stain indicating rich neurosecretory material during both breeding and nonbreeding season. The median eminence (MI) is located at the anterior part of neurohypophysis and sends portal capillaries to adenohypophysis.

Differential Regulation of Gonadotropins as Revealed by Transcriptomes of Distinct LH and FSH Cells of Fish Pituitary

“…The evolutionary tree includes only organisms with known information regarding their GtH distribution in the pituitary. Information regarding each organism was obtained from: Mouse ( Mus musculus ) [ 26 , 27 ], dogs ( Canis lupus familiaris ) [ 28 ], pigs ( Sus scrofa domesticus ) [ 29 ], human ( Homo sapiens ) [ 30 ], sheep ( Ovis aries ) [ 31 ], horse ( Equus ferus caballus ) [ 32 ], cow ( Bos Taurus ) [ 33 ], lamprey ( Petromyzon marinus ) [ 34 ], Saddled bichir ( Polypterus endlicherii ) [ 35 ], tilapia ( Oreochromis niloticus ) [ 17 ], carp ( Cyprinus carpio ) [ 36 ], salmon ( Salmo salar ) [ 37 ], sturgeon ( Acipenser gueldenstaedtii ) [ 38 ], turtle ( Geoclemys reevesii ) [ 39 ], chicken ( Gallus gallus ) [ 24 ], duck ( Anas acuta ) [ 40 ], lizard ( Calotes versicolor ) [ 41 ], and frog ( Rana japonica ) [ 42 ]. Rostral pars distalis (RPD), proximal pars distalis (PPD), pars intermedia (PI), pars nervosa (PN), pars distalis (PD), juxtaneural pars tuberalis (juxPT), pars tuberalis interna (PTint), pars tuberalis (PT), median eminence (ME), cephalic pars distalis (CePD), caudal pars distalis (CaPD), adenohypophysis (AdH), neurohypophysis (NuH).…”

Reactive scope model and emergency life history stage provide useful tools for evaluating the stress responses of native Australian lizards living in disturbed landscapes

“… A diagram illustrating the general mechanism of physiological stress response in reptiles. Numbers in square brackets indicate references specific to adjoining comment: [1] Graham et al (2012) , [2] Sheriff et al (2011) , [3] Pecoraro et al (2006) , [4] Berkvens (2012) , [5] Neuman-Lee et al (2020) , [6] Narayan (2019) , [7] Moore and Jessop (2003) , [8] Morici et al (1997) , [9] Holliday et al (2009) , [10] Thaker et al (2010) , [11] Romero et al (2009) , [12] Dunlap (1995) , [13] Silvestre (2014) , [14] Wyneken (2007) , [15] Malashetty et al (2009) and [16] Di Lorenzo et al (2020) . …”