Results suggest that adult cat serum may be used as an immunoglobulin supplement in colostrum-deprived kittens. Although the minimum concentration of IgG necessary to protect kittens from infection is unknown, concentrations achieved were comparable to those in kittens that suckled normally.

We examined the chromosomal basis for the synthesis of tissue (ovary, endometrium/placenta, and peri-implantation blastocyst) isoforms of cytochrome P450 aromatase in the pig. DNA fragments derived from three distinct porcine aromatase chromosomal genes were cloned and characterized. The porcine type III aromatase gene encoding the blastocyst aromatase isoform was found to consist of nine coding exons and two mutually exclusive, 5' untranslated exons (designated E1A and E1B), collectively spanning 30 kb or more. The porcine type II aromatase gene, encoding the endometrial/placental aromatase isoform, was identified by cloning of a genomic DNA fragment spanning the corresponding exons 7, 8, and 9. The DNA inserts of two other phage clones encompassed exons 2, 3, and 4 of a third chromosomal gene (type I) encoding the ovarian aromatase isoform. All intron-exon junctions in these genomic fragments were found to be identical in relative positions to those of the single-copy human aromatase gene. Comparisons of cDNA and genomic sequences indicated that nucleotide sequence variation was not uniform across the corresponding exons of these genes and that the corresponding intronic sequences were conserved. The type II and type III aromatase genes were localized to the same regional location (q16-17) on swine chromosome 1, which is homologous to the human chromosome 15 region (q21.1) in which the human aromatase gene resides. Results demonstrate that the three aromatase genes characterized in the present study appear to be similar in their overall structural organization and most likely are clustered, which could have resulted from at least two independent gene duplication events. The presence of multiple aromatase genes constitutes a newly described mechanism by which aromatase enzyme biosynthesis and functional activity can be regulated in a tissue and temporal fashion and serves to highlight further the complexity of aromatase gene expression in mammals. Moreover, the presence of a unique aromatase gene that is highly expressed in pig blastocysts may constitute a paradigm for other mammals (e.g., equids, rabbit, hamster) whose peri-implantation blastocysts are estrogenic.

Pig blastocysts exhibit a transient period of estrogen production at periimplantation, with a second, more sustained period of estrogen synthesis occurring in endometrium and placenta at later pregnancy. Previously we reported the isolation of cDNA clones encoding a novel isoform of cytochrome P450 aromatase (the terminal enzyme in the estrogen biosynthetic pathway) from porcine periimplantation blastocysts. The present study investigated pregnancy-associated expression, in blastocysts and maternal reproductive tract tissues of this and an additional mRNA transcript encoding a distinct P450 aromatase isoform. Restriction endonuclease and nucleotide sequence analyses of 44 cDNA clones demonstrated that the major aromatase mRNA in periimplantation blastocysts and early-pregnancy endometrium and placenta (blastocyst-type) differed in sequence from the major aromatase mRNA expressed in endometrium and placenta at midpregnancy (endometrial-type). The deduced blastocyst and endometrial aromatase isoform protein sequences had 93% similarity. A third type of aromatase mRNA, deleted in exons 4-6 sequences, also was cloned from blastocysts. This cDNA was identical in nucleotide sequence to the blastocyst full-length aromatase cDNA and specified an open reading frame of 354 amino acids for a putative aromatase-related protein containing the heme-binding domain. Expression of this shorter mRNA in blastocysts was confirmed by reverse transcription polymerase chain reaction. The 5'-untranslated exon sequences in the transcripts encoding the blastocyst-type aromatase isoform were distinct from that of the endometrial type, consistent with differential expression of multiple chromosomal genes. In periimplantation equine embryos, however, embryonic and placental 5'-untranslated exon-containing transcripts were coexpressed. Results identify an aromatase isoform expressed in the endometrium and placenta at midpregnancy, demonstrate a transition in synthesis of aromatase isoform-specific mRNAs during placental development, and suggest the preferential involvement of the blastocyst aromatase isoform in synthesis of estrogenic molecules that may function in embryo-maternal signaling at periimplantation.

No abstract

After parturition, immune functions such as lymphocyte response to mitogens and production of antibodies are depressed in dairy cows. Dietary regimens that improve the immune function of dairy cows after calving may improve uterine health and lead to earlier breeding after parturition. The objective of this study was to examine the effect of feeding a calcium salt of trans isomers of fatty acids (tFA) to periparturient Holstein cows on plasma biomarkers of inflammation. Dietary treatments were initiated approximately 28 d before expected calving date and continued through d 21 postpartum. Prepartum and postpartum diets were formulated to be isolipidic, containing 1.5% saturated fats (n = 15) or 1.8% tFA (n = 15). Multiparous cows were heavier at calving (+32%) and produced more milk (+17%) than primiparous cows. Periparturient tFA supplementation increased plasma PGF(2alpha) metabolite concentration in multiparous cows, but not in primiparous cows. Concentrations of prostaglandin E(2), tumor necrosis factor-alpha, and interleukin-4 in plasma did not differ between diets and parities. Results raise the possibility that peripartum tFA supplementation may affect uterine health and reproductive efficiency of early lactation dairy cows through alteration of peripheral PGF(2alpha) concentration.