Fertility and genomics: comparison of gene expression in contrasting reproductive tissues of female cattle

Abstract

To compare gene expression among bovine tissues, large bovine RNA-seq datasets were used, comprising 280 samples from 10 different bovine tissues (uterine endometrium, granulosa cells, theca cells, cervix, embryos, leucocytes, liver, hypothalamus, pituitary, muscle) and generating 260 Gbases of data. Twin approaches were used: an information-theoretic analysis of the existing annotated transcriptome to identify the most tissue-specific genes and a de-novo transcriptome annotation to evaluate general features of the transcription landscape. Expression was detected for 97% of the Ensembl transcriptome with at least one read in one sample and between 28% and 66% at a level of 10 tags per million (TPM) or greater in individual tissues. Over 95% of genes exhibited some level of tissue-specific gene expression. This was mostly due to different levels of expression in different tissues rather than exclusive expression in a single tissue. Less than 1% of annotated genes exhibited a highly restricted tissue-specific expression profile and approximately 2% exhibited classic housekeeping profiles. In conclusion, it is the combined effects of the variable expression of large numbers of genes (73%-93% of the genome) and the specific expression of a small number of genes (<1% of the transcriptome) that contribute to determining the outcome of the function of individual tissues.

In vitro generation of polysialylated cervical mucins by bacterial polysialyltransferases to counteract cytotoxicity of extracellular histones

“…In summary, the HPLC-based characterization of cervical mucins revealed the presence of oligoSia chains and verified the results of the polySiaT activity assay demonstrating that bovine cervical mucins can be used as an acceptor for bacterial polySiaT. Interestingly, expression data from bovine cervix and uterus already demonstrated that mRNA of different a2,8-sialyltransferases are present in the female reproductive tract [37,38]. However, until now it is not known, which mammalian a2,8-sialyltransferase can use glycans on mucins as an acceptor.…”

Transcriptome analyses identify five transcription factors differentially expressed in the hypothalamus of post- versus prepubertal Brahman heifers1

“…To confirm "typical" hypothalamic gene expression from this list of expressed genes is challenging. A recent study of female cattle tissues found that less than 1% of annotated genes presented a restricted tissue-specific expression (McGettigan et al, 2016). The 10 most hypothalamicspecific genes, according to McGettigan et al (2016), were expressed in all our samples (RPKM > 0.2 in each ◊ sample) and did not differ between postpubertal and prepubertal heifers.…”

“…A recent study of female cattle tissues found that less than 1% of annotated genes presented a restricted tissue-specific expression (McGettigan et al, 2016). The 10 most hypothalamicspecific genes, according to McGettigan et al (2016), were expressed in all our samples (RPKM > 0.2 in each ◊ sample) and did not differ between postpubertal and prepubertal heifers. These 10 genes, including the most specific myelin proteolipid protein, might be considered constitutively expressed in the hypothalamus because they could be confirmed by others and were independent of developmental status in our samples (P > 0.05).…”

Expresión génica en células de granulosa bovinas de folículos en crecimiento

“…6/8 Encontrar la expresión de genes asociados a la unión, está de acuerdo con la naturaleza fisiológica de los folículos que en ese tamaño son un tejido proliferativo que para su desarrollo necesita una gran cantidad de RNA mensajeros de señales (18) para cumplir su función: inmediata de ovulación e indirectamente un oocito competente para formar un embrión. Otros trabajos donde hay comparación de expresión diferencial en folículos informan que existen en los búfalos 110 genes diferencialmente expresados pertenecientes a 14 vías metabólicas y que para las vacas se encontraron 446 genes que pertenecían a 10 vías metabólicas (14).…”