التفاصيل البيبلوغرافية
| العنوان: |
Stereological point-counting; an accurate method for assessing ovarian function in tilapia |
| المؤلفون: |
Coward, K. kevin.coward@pharm.ox.ac.uk, Bromage, N.R.1 |
| المصدر: |
Aquaculture. Sep2002, Vol. 212 Issue 1-4, p383. 19p. |
| مصطلحات موضوعية: |
*TILAPIA zillii, *FISHERIES, *REPRODUCTION |
| مستخلص: |
We discuss the use of stereology in fisheries research and by presenting novel data, along with comparisons to conventional methodology, further confirm the effectiveness of a point-counting method that estimates the relative distributions of oocyte developmental stages within an asynchronous ovary. Point-counting methodology was applied in three experiments involving the ovaries of Tilapia zillii (Gervais), a teleost that exhibits highly asynchronous ovarian development. Quantitative data were first obtained from conventional digestion of ovarian tissue with mercury-based Gilson''s Fluid and compared to that derived from stereology. Analysis of covariance demonstrated no significant difference (P≥0.05) between counts of discrete oocyte developmental stages determined by either method. However, counts of post-ovulatory follicles (POFs) using Gilson analysis were not possible, due to the highly irregular size and shape of these structures. A second experiment compared an immediately post-spawned ovary with an ovary 5 days after spawning, presenting comparative data determined by stereology and Gilson digestion; on this occasion, Gilson analysis significantly underestimated the proportion of atretic ooytes (P<0.05). A further experiment forms a preliminary investigation of the effect of intra-muscular injections of human chorionic gonadotropin (hCG) upon early ovarian recrudescence and is presented as an example to demonstrate the highly informative nature of stereological analysis; injections of hCG on 3 days after spawning resulted in a significant decrease of stage 5 (early vitellogenic) but significant increase of stage 6 (late vitellogenic/maturing) oocytes by day 5. We conclude that point-counting stereology is a powerful technique for the quantitative analysis of ovarian development. Moreover, stereology avoids the prolonged use of dangerous mercury-based solutions and classifies oocytes into discrete developmental stages using a combination of criteria (biochemical, histological and size distribution) and not simply oocyte size. [Copyright &y& Elsevier] |
| قاعدة البيانات: |
Academic Search Index |
