Pregnancy induces extensive changes of transcript usage in the goat brain

Gestation induces strong anatomical, histological and transcriptomic changes in the pregnant female brain. Our study aimed to characterize the RNA transcripts expressed in the goat brain and their main structural, transcriptional, and functional features, while also exploring whether 2-mo (57 d) pregnancy affects transcript usage in the brain. Twelve brain tissue samples from three 2-mo pregnant and 4 nonpregnant Murciano-Granadina goats were sequenced. A total of 62,185 transcripts from 29,043 genes (averaging ∼2.14 transcripts per gene) were detected, and ∼60% of them were novel transcripts or novel loci. Transcript usage in the brain tissues of pregnant goats revealed widespread changes in alternative splicing. A total of 2,004 genes (18.14% of all expressed multitranscript genes) exhibited significant shifts in transcript usage in response to 2-mo pregnancy. The hippocampus displayed the most substantial changes, with 689 differentially used transcripts from 545 genes. Other tissues showing notable shifts were the pineal gland (374 transcripts), the olfactory bulb (301 transcripts), and the adenohypophysis (281 transcripts). In contrast, the pons showed a markedly lower level of differential transcript usage in response to pregnancy. These results provide evidence that the adaptive response of the brain to pregnancy is mediated not only by changes in gene expression, but also by the preferential use of specific gene isoforms.