TITLE:
The Effects of Letrozole in Transfer of Maternal Immunity against Lactococcosis to Eggs and Larvae in Rainbow Trout (Oncorhynchus mykiss, Walbaum)
AUTHORS:
Paria Akbary, Ali Reza Mirvaghefi, Mostafa Akhlaghi, Bagher Majazi Amiri, Mohammad Saeid Fereidouni
KEYWORDS:
Maternal Transfer, Immunoglobulin, Lysozyme, Lactococcosis, Rainbow Trout
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.6 No.2,
February
12,
2015
ABSTRACT: This study evaluated transfer of maternal lysozyme and immunoglobulin (IgM) against Lactococcus garviea, the causative agent of lactococcosis to eggs and larvae in rainbow trout. Changes in circulating lysozyme and IgM during development of eggs and larvae were measured by a method based on the ability of lysozyme to lyse the bacterium Micrococcus lysodeikticus and enzyme-linked immunosorbent assay (ELISA) respectively. For doing this, twelve broodstocks were injected weekly with 2.5 mg·kg-1 letrozole (an endocrine disrupter component) two months before spawning season and vaccinated intraperitoneally (i.p) with a bacterin (inactivated L. garviae) one month before spawning. Twelve broodstocks for vaccination and twelve female rainbow trouts as control group were also immiunised (i.p) with the bacterin and injected (i.p) with PBS respectively. Results showed that at day 8 after hatching, lysozyme and IgM levels during pre-larval stages decreased gradually, as yolks were absorbed. Lysozyme and IgM levels were significantly higher in the letrozole injected immiunised parents 30 days after immunisation as well as their larvae compared to the control group (p L. garviae) (one month before spawning) in maternal transfer of lysozyme and IgM levels to eggs and larvae.