Study of atresia in the ovary during the annual reproductive cycle and nesting cycle of the pied myna

Abstract

Atretic follicles of the ovary of the Indian pied myna (Sturnus contra contra) were studied in birds collected each month throughout the year. Histological examination included histochemical techniques for 3β-hydroxy-steroid dehydrogenase (3β-HSDH) and for lipids. Atretic follicles were mainly of two types: nonbursting (lipoidal and cystic) and bursting (Types I-VI). Nonbursting atresia was observed in the smaller follicles (< 500 μm in diameter), whereas larger follicles (> 500 μm in diameter, viz., small developing, large developing, and yolky follicles) showed exclusively a bursting type of atresia. Sudanophilic lipid was found in both types (lipoidal and cystic) of nonbursting atresia, but was present only in early stages of bursting atresia. Activity of 3β-HSDH was absent in nonbursting atresia, but present in early stage of bursting atresia. Nonbursting atresia was common throughout the year and higher in frequency than the bursting type. Bursting atresia was common during March through May and attained its peak level during the nesting cycle.

Histological study of follicular atresia in the ovary of the domestic hen (Gallus domesticus)

“…Our results show that this is not usually the case because in Type 2 atretic follicles, which are common, the yolk escapes through the rupture site into the stroma and hence is outside the follicle. A similar observation was made by Gupta & Maiti (1986) in the Indian pied myna ovary.…”

“…By considering the three dimensional picture of the follicle with a small rupture site on one side, it is obvious that the probability is large of missing this point of rupture in histological sections. Possibly this is the most likely explanation why earlier workers, who examined only a few representative sections of the ovary, did not appre¬ ciate such frequent occurrence of bursting atresia in the hen (Fell, 1925;Deol, 1955;Uhrin, 1984) or most other birds (see references in Gupta & Maiti, 1986). Different kinds of atretic structures considered earlier to be the involution or invasion type (Saidapur, 1978;Gilbert, 1979) were in fact always found in semi-serial sections to be of Type 2.…”

“…This has been thought to be the most common type. However, Gupta & Maiti (1986) have demonstrated that, in the ovary of the Indian pied myna, all larger follicles ( > 500 pm diameter) undergo bursting atresia whereas atresia of smaller follicles ( < 500 pm diameter) is of the non-bursting type. Whether the atretic process is similar in the ovary of the domestic hen remains to be determined because evidence from earlier studies is equivocal (Fell, 1925;Deol, 1955;Uhrin, 1984).…”

“…This has led to subjective assessment of atresia in birds, and the use of different names and systems of classification; e.g. 2-6 types of follicular atresia in birds have been reported (see Gupta & Maiti, 1986). It remains doubtful whether these discrepancies are real or are the result of problems related to technique and/or interpretation (Gilbert, 1979;Gupta, 1983).…”

Structural and cuantitative aspects of the ovary of the Fulica armillata (Aves: Rallidae)

“…Nili y Kely (1996) han demostrado que, el sistema lacunar del ovario de G. domesticus provee a los folículos bursting de un espacio voluminoso para que el vitelo allí depositado sea luego metabolizado por las células fagocíticas. La atresia folicular de F. armillata muestra similitudes morfológicas con las descriptas en el ovario de diferentes especies de aves silvestres por diferentes autores (Halse 1985, Gupta & Maití 1986, Gupta et al 1988, Guraya 1989b, Bulfon & Bee de Speroni 2003, Madekuroswa & Kimaro 2006, Claver et al 2008). …”