Boar seminal plasma: current insights on its potential role for assisted reproductive technologies in swine.

Seminal plasma (SP) supports not only sperm function but also the ability of spermatozoa to withstand biotechnological procedures as artificial insemination, freezing or sex sorting. Moreover, evidence has been provided that SP contains identifiable molecules which can act as fertility biomarkers, and even improve the output of assisted reproductive technologies by acting as modulators of endometrial and embryonic changes of gene expression, thus affecting embryo development and fertility beyond the sperm horizon. In this overview, we discuss current knowledge of the composition of SP, mainly proteins and cytokines, and their influence on semen basic procedures, such as liquid storage or cryopreservation.

Influence of insemination time on the fertility of sex sorted frozen-thawed Y-sperm in red deer.

The aim of this study was to assess the effect of insemination timing on pregnancy rates in red deer (Cervus elaphus) when using sex-sorted sperm samples. Semen was collected by electroejaculation from 8 mature stags and processed to obtain: Conventional samples, following standard freezing procedures for commercial purposes; Control sorted samples, diluted and handled as per sorted samples but without being submitted to the sorter passage; and Y Sex Sorted (YSS) samples. Hinds were synchronized via intravaginal CIDR (Controlled Internal Drug Release) placement and given eCG (Folligon PMSG Serum Gonadotrophin) on day 12, upon CIDR removal.

Optimization of protocols for Iberian red deer (Cervus elaphus hispanicus) sperm handling before sex sorting by flow cytometry.

Currently, sperm reproductive biotechnologies such as sex sorting and cryopreservation are undoubtedly valuable tools for improving the economic and biological efficiency of red deer production systems. In this context, and because of the particular characteristics of this species (extensive exploitation typically far from laboratory facilities), a key goal is to optimize the design of an adequate handling protocol of sperm samples before samples are subjected to sex sorting and cryopreservation procedures to obtain better outputs from the application of these technologies. The main aim of this paper was to design an adequate protocol for Iberian red deer sperm handling before sex sorting by flow cytometry to obtain optimal yields when sex sorting is used in this species.

Effects of rapid cooling prior to freezing on the quality of canine cryopreserved spermatozoa.

The aim of this study was to evaluate the effects of rapid cooling prior to freezing on frozen-thawed canine sperm quality. In experiment 1, centrifuged ejaculates from 6 dogs were pooled, split into 4 aliquots and cryopreserved by the Uppsala procedure using different cooling rates (control, cooling speed 18 C/90 min and average cooling rate 0.2 C/min; rapid, cooling speed 18 C/8 min and average cooling rate 2.

The battle of the sexes starts in the oviduct: modulation of oviductal transcriptome by X and Y-bearing spermatozoa.

Background: Sex allocation of offspring in mammals is usually considered as a matter of chance, being dependent on whether an X- or a Y-chromosome-bearing spermatozoon reaches the oocyte first. Here we investigated the alternative possibility, namely that the oviducts can recognise X- and Y- spermatozoa, and may thus be able to bias the offspring sex ratio.

Results: By introducing X- or Y-sperm populations into the two separate oviducts of single female pigs using bilateral laparoscopic insemination we found that the spermatozoa did indeed elicit sex-specific transcriptomic responses.

Effects of Hoechst 33342 staining and ultraviolet irradiation on mitochondrial distribution and DNA copy number in porcine oocytes and preimplantation embryos.

Hoechst 33342 (H342), in combination with ultraviolet (UV) irradiation, is frequently used to aid or confirm the enucleation of porcine oocytes in somatic cell nuclear transfer programs. The exposure of oocytes to H342 and UV irradiation has a deleterious effect on the development of in vitro-fertilized porcine oocytes, with increasing exposure to UV irradiation (up to 30 sec) having more drastic effects. It has been hypothesized that this decrease in embryonic development could be due to damage to the mitochondrial DNA (mtDNA).

Improving the efficiency of sperm technologies in pigs: the value of deep intrauterine insemination.

The use of AI in pigs has dramatically expanded in the last few years. New methodological advances in AI are required to serve the requirements of new sperm technologies, such as the use of low dose AI, because the use of cervical AI has a very low efficiency leading to low fertility results. One of the strategies devised to meet these requirements is the deposition of semen near the site of fertilization in the oviduct.

Effects of centrifugation before freezing on boar sperm cryosurvival.

Current protocols for boar sperm cryopreservation require the centrifugation of semen in order to separate sperm cells from the seminal plasma. This study evaluated the influence of different centrifugation regimes on both sperm recovery and yield (percentage of viable sperm with an intact acrosome relative to the initial sperm population) after centrifugation (experiment 1) as well as the influence of different centrifugation regimes on boar sperm cryosurvival (experiment 2). In both experiments, sperm-rich fractions from 3 boars were diluted, pooled, and cooled to 17 degrees C before centrifugation.

Fertility of weaned sows after deep intrauterine insemination with a reduced number of frozen-thawed spermatozoa.

The present study evaluates the effectiveness of the transcervical deep intrauterine insemination (DUI) with a reduced number of frozen-thawed boar spermatozoa in weaned sows. DUI was performed using a specially designed flexible device (length 180 cm, outer diameter 4mm, working channel 1.8mm, working channel's volume 1.

Birth of piglets after deep intrauterine insemination with flow cytometrically sorted boar spermatozoa.

The present study was carried out to determine the pregnancy rates, farrowing rates and litter size in sows with either induced or spontaneous ovulation inseminated with flow cytometric sorted spermatozoa using deep intrauterine insemination technology. Spermatozoa were stained with Hoechst 33342 and sorted by flow cytometry/cell sorting but not separated into separate X and Y populations. In Experiment 1, sows (n=200) were weaned and treated for estrus/ovulation induction with eCG/hCG.