High production of transfer RNAs identifies the presence of developing oocytes in ovaries and intersex testes of teleost fish

Method for the molecular and quantitative identification of oocytes and their developmental stage in teleost fish gonads

“…These high levels of 5S rRNA and tRNAs transcription can be used to distinguish the presence of oocytes in teleost gonads, as demonstrated in multiple fish species [1 , 6 , 7] . In addition, this can be also used for the identification of intersex individuals, because transcription levels are intermediate between testis and ovary [6 , 7] . Some contaminants present in the marine environment behave as endocrine disrupting compounds (EDCs).…”

“…Ribogenesis has been estimated to be the most energetically-demanding process in the cell, so the regulation of the complex array of rRNAs and proteins necessary to produce new ribosomes is a major factor determining the potential of a cell to grow and divide [3 , 4] even more for a growing oocyte. RNA polymerase III (Pol-III) is in charge of synthesizing the 5S ribosomal RNAs and the tRNAs [1 , 5 , 6] . Fish accumulate high concentrations of 5S rRNA and tRNAs in previtellogenic oocytes; up to 90% of the total RNA in the ovary of some fish [5 , 6] .…”

“…RNA polymerase III (Pol-III) is in charge of synthesizing the 5S ribosomal RNAs and the tRNAs [1 , 5 , 6] . Fish accumulate high concentrations of 5S rRNA and tRNAs in previtellogenic oocytes; up to 90% of the total RNA in the ovary of some fish [5 , 6] . Later, during secondary growth and vitellogenesis, oocytes begin to accumulate the longest 5.8S, 18S and 28S rRNAs [1 , 5 , 6] under the regulation of RNA polymerase I (Pol-I).…”

“…Fish accumulate high concentrations of 5S rRNA and tRNAs in previtellogenic oocytes; up to 90% of the total RNA in the ovary of some fish [5 , 6] . Later, during secondary growth and vitellogenesis, oocytes begin to accumulate the longest 5.8S, 18S and 28S rRNAs [1 , 5 , 6] under the regulation of RNA polymerase I (Pol-I). In previtellogenic oocytes 5S rRNAs are stored in cytosolic ribonucleoproteic particles.…”

Identification of sex-biased miRNA markers informative of heat-past events

“…Quality of the samples was assessed by BioAnalyzer (2100 Bioanalyzer, Agilent Technologies) with ratio 260/280= 2.07 ± 0.04 and 260/230=1,73 ± 0,24) and by the RNA Integrative Number (RIN) measured with a Bioanalyzer (Agilent Technologies, USA) with values > 9.2 in testis. In ovary, RIN numbers were not considered due to naturally high levels of 5s rRNA and tRNA (Bir et al, 2023; Mazabraud et al, 1975)…”