adenohypophysis

Null cell adenoma--a separate category not clearly reflected in the developmental biology of the anterior pituitary--was defined by Kovacs et al (24) as pituitary adenoma unassociated clinically or biochemically with increased hormone secretion and containing no adenohypophyseal hormones by immunohistochemistry and by electron microscopy; null cell adenoma accounted for approximately 16% of their series of 343 surgically removed adenomas.

Craniopharyngioma is a metaplasia of adenohypophyseal cells in the pituitary stalk or gland.

Non genetic hypotrichosis in calves is associated with conditions such as iodine deficiency, adenohypophyseal hypoplasia and intrauterine infection with bovine virus diarrhoea virus (Hanna and Oglive, 1989).

Adenohypophyseal secretory cells include somatotrophs (nearly 50%), which produce somatotropin (growth hormone, GH); corticotrophs (15-20%), which release adrenocorticotropic hormone; gonadotrophs (10-15%), which synthesize luteinizing hormone and follicle stimulating hormone; thyrotrophs (3-5%), which release thyroid stimulating hormone; and lactotrophs (10-25%), which release prolactin (PRL) (5).

This timing is further supported by observations of karyotype expansion between Cyclostomata and Gnathostomata (Nakatani et al., 2007) and earlier reconstructions of other gene families, including homeobox (Neidert et al., 2001; Force et al., 2002; Tank et al., 2009), pigmentation genes (Braasch et al., 2008), vitellogenin (Finn and Kristoffersen, 2007; Babin, 2009; Finn et ai, 2009; Kristoffersen et al., 2009), chemosensory receptors (Libants et al., 2009), adenohypophyseal hormones (Kawauchi and Sower, 2006; Sower et al., 2008), and thyroid and glycoprotein hormone receptors (Freamat and Sower, 2008; Chauvigne et al., 2010; Applebaum et al., 2012).