Bioscientifica Proceedings

During mammalian diapause, the embryo is arrested at the blastocyst stage. In diapausing carnivores and marsupials, growth arrest of the blastocyst is coincident with a quiescent corpus luteum (CL). In the roe deer, progesterone is produced throughout diapause and the blastocyst exhibits very slow growth. To date, early roe deer embryos of known age have not been described. Therefore, it is not known at which stage and at what pace the roe deer embryo enters diapause. To colle...

Manipulation of the pig genome is currently restricted to the random insertion of new DNA using pronuclear microinjection. This method suffers from a number of inherent limitations, the majority of which result from the inability to control the site at which the transgene becomes integrated. These drawbacks, together with the need to be able to target existing genes, will result in the replacement of pronuclear injection by new methods that have the capability to direct i...

Numerous corpora lutea form from the multiple follicles that ovulate during the oestrous cycle of pigs. Vascular elements invade the follicle from the theca compartment, first centripetally, and subsequently by lateral branching of centripetal veins and arteries. The vessels are the vehicle for dispersion of steroidogenic theca cells throughout the corpus luteum. Mitosis occurs in both the theca and granulosa layers before ovulation, and in luteal cells well into the lut...

With the advent of next generation sequencing platforms (RNA-seq), transcriptional profiling permits the characterization of millions of RNAs from even the most limiting samples like early embryos. High-throughput RNA-seq can generate over 600 gigabases (Gb) in a single sequencing run, providing a near-complete record of all of the genes expressed in a sample at the time of collection. Condensing and finding coherence in the immense amount of raw data generated by transc...

The introduction of high-density SNP arrays in livestock species has enabled genomic evaluations on a scale not possible just a few years ago. Faster genetic gains are realized from application of genomics in pigs by increasing the accuracy of selection. This is especially important for lowly heritable reproductive traits, where female selection candidates have not yet expressed a phenotype at the point of selection and male candidates have no phenotype at all. Litter si...

The introduction of high-density SNP arrays in livestock species has enabled genomic evaluations on a scale not possible just a few years ago. Faster genetic gains are realized from application of genomics in pigs by increasing the accuracy of selection. This is especially important for lowly heritable reproductive traits, where female selection candidates have not yet expressed a phenotype at the point of selection and male candidates have no phenotype at all. Litter si...

The extensive use of embryo technologies has emphasized the need for assessing embryo quality by morphological techniques, such as transmission electron microscopy, immunocytochemistry for confocal laser scanning microscopy and fluorescence in situ hybridization. By a combination of these techniques, it has been possible to demonstrate: (i) that rRNA gene activation, as monitored by embryonic nucleolar development, is comparable in bovine embryos developed in vivo...

During ejaculation in the boar, sperm cohorts emitted in epididymal cauda fluid are sequentially exposed and resuspended in different mixtures of accessory sex gland secretion. This paper reviews the relevance of such unevenly composed fractions of seminal plasma (SP) in vivo on sperm transport and sperm function and how this knowledge could benefit boar semen processing for artificial insemination (Al). The firstly ejaculated spermatozoa (first 10 ml of the spe...

Abstract unavailableKeywords: corpus luteum; sheep; protein kinase C; calcium; phosphoinositide turnover© 1991 Journals of Reproduction & Fertility Ltd...

Abstract unavailableKeywords: progesterone; protein kinase C; intracellular calcium; prostaglandins; arachidonic acid; luteal cells; cattle© 1991 Journals of Reproduction & Fertility Ltd...