Ribosome RNA Profiling to Quantify Ovarian Development and Identify Sex in Fish

  1. Ribosome RNA Profiling to Quantify Ovarian Development and Identify Sex in Fish

Figure 1

Ribosome RNA (rRNA) profiling in gonads as powerful sex marker in species displaying synchronous (yellow perch) and asynchronous (bluegill and largemouth bass) ovary development. Three indexes, percent of 5S rRNA relative to total RNA (5S rRNA/total RNA %), the natural logarithm of 5S/18S rRNA [Ln(5S/18S rRNA)], and percent of 18S rRNA relative to total RNA (18S rRNA/total RNA) were applied. (a) Yellow perch (n = 33), 5S rRNA/total RNA and 5S/18S rRNA can both distinguish females from males unambiguously from early ovary development up to four months (November point) before spawning season, but can’t later on; 18S rRNA/total RNA can distinguish females from males unambiguously only at early ovary development stages. (b) Bluegill (n = 37), 5S rRNA/total RNA and 5S/18S rRNA can both distinguish females from males unambiguously throughout the reproductive cycle; 18S rRNA/total RNA can distinguish females from males unambiguously only at early ovary development stages (about GSI < 4.00). (c) Largemouth bass (n = 7), three indexes can all distinguish females from males unambiguously at any ovary development stages. Histological images indicate synchronous development of oocytes in yellow perch, and asynchronous development in bluegill and largemouth bass. GSI, gonadosomatic index.