Detection of quantitative trait loci for growth and fatness in pigs

A quantitative trait locus (QTL) analysis of growth and fatness data from a three-generation experimental cross between Meishan (MS) and Large White (LW) pig breeds is presented. Six boars and 23 F1 sows, the progeny of six LW boars and six MS sows, produced 530 F2 males and 573 F2 females. Nine growth traits, i.e. body weight at birth and at 3, 10, 13, 17 and 22 weeks of age, average daily gain from birth to 3 weeks, from 3 to 10 weeks and from 10 to 22 weeks of age, as well as backfat thickness at 13, 17 and 22 weeks of age and at 40 and 60 kg live weight were analysed. Animals were typed for a total of 137 markers covering the entire porcine genome. Analyses were performed using two interval mapping methods: a line-cross (LC) regression method where founder lines were assumed to be fixed for different QTL alleles and a half-/full-sib (HFS) maximum likelihood method where allele substitution effects were estimated within each half-/full-sib family. Both methods revealed highly significant gene effects for growth on chromosomes 1, 4 and 7 and for backfat thickness on chromosomes 1, 4, 5, 7 and X, and significant gene effects on chromosome 6 for growth and backfat thickness. Suggestive QTLs were also revealed by both methods on chromosomes 2 and 3 for growth and 2 for backfat thickness. Significant gene effects were detected for growth on chromosomes 11, 13, 14, 16 and 18 and for backfat thickness on chromosome 8, 10, 13 and 14. LW alleles were associated with high growth rate and low backfat thickness, except for those of chromosome 7 and to a lesser extent early-growth alleles on chromosomes 1 and 2 and backfat thickness alleles on chromosome 6.     

Possible relationships between SLA and porcine reproduction

The possible influence of the pig major histocompatibility complex on reproductive traits is reviewed. Among the parameters investigated, significant associations were observed between SLA and genital tract development in males. Several SLA haplotypes affected either positively or negatively the development of testes, the epididymes and the Cowper's glands, whereas the influence of these haplotypes on androsterone tissue content was limited. The impact of the SLA complex on female reproductive performance has been more difficult to ascertain, although some results suggest that the SLA region may interfere with ovulation rates. The influence on prolificacy of SLA sharing between sires and dams was also investigated. Even if fertilization rate is not affected, embryonic mortality and preimplantation embryo development might be influenced by the pig MHC region. Although the litter size was not only marginally affected by the SLA complex, there is one case where SLA identity between the boar and several related sows led to significantly reduced litter size. In these families piglets homozygous for a particular SLA haplotype were almost absent, suggesting the existence of a recessive lethal gene linked to SLA.     

Use of very low density light fluorescence microscopy: study of real-time of the development of chromatin of unicellular mouse embryos

Video enhanced fluorescence microscopy coupled to digitized image processing was used to follow the dynamics of chromatin changes in live one cell mouse embryos. The experimentation on live material was made possible through the use of very low concentrations of the DNA specific fluorophore, Hoechst 33342, and very low irradiation intensities, which maintain a good viability of embryos.     

Effects of leucine-enkephalin and methionine-enkephalin on prolactin and gonadotropin secretion and synthesis in vitro

In vivo, Enkephalins, stimulate PRL, inhibit LH and are inactive on FSH. However, in monolayer pituitary cell cultures, PRL, LH and FSH secretions and synthesis are not modified by Met-Enk. (5 microgram/ml) or Leu-Enk. (5 and 10 microgram/ml). But the simultaneous presence of LHRH and Enk. induces an increase in LH secretion and synthesis without modifying FSH and PRL. In conclusion 1) Enk do not act by themself at the pituitary level but 2) they are able to modify the responses induced by hypothalamic hormones.     

Computer‐aided biochemical programming of synthetic microreactors as diagnostic devices

Biological systems have evolved efficient sensing and decision‐making mechanisms to maximize fitness in changing molecular environments. Synthetic biologists have exploited these capabilities to engineer control on information and energy processing in living cells. While engineered organisms pose important technological and ethical challenges, de novo assembly of non‐living biomolecular devices could offer promising avenues toward various real‐world applications. However, assembling biochemical parts into functional information processing systems has remained challenging due to extensive multidimensional parameter spaces that must be sampled comprehensively in order to identify robust, specification compliant molecular implementations. We introduce a systematic methodology based on automated computational design and microfluidics enabling the programming of synthetic cell‐like microreactors embedding biochemical logic circuits, or protosensors, to perform accurate biosensing and biocomputing operations in vitro according to temporal logic specifications. We show that proof‐of‐concept protosensors integrating diagnostic algorithms detect specific patterns of biomarkers in human clinical samples. Protosensors may enable novel approaches to medicine and represent a step toward autonomous micromachines capable of precise interfacing of human physiology or other complex biological environments, ecosystems, or industrial bioprocesses.     

Quail Egg Yolk: A Novel Cryoprotectant for the Freeze Preservation of Poitou Jackass Sperm

For many years, attempts have been made to establish a sperm bank for the Poitou jackass population which is threatened with extinction. Unfortunately, no cryopreservation technique has ever been described for spermatozoa of this species. In an attempt to find a suitable technique, we studied the relative effectiveness of chicken egg yolk and quail egg yolk in preserving the motility and characteristics of movement of Poitou jackass spermatozoa during the freezing–thawing process. Semen was diluted to 60 × 10⁶sperm/ml in a preservation medium containing 4% (v/v) glycerol with 0, 2, 5, 10, 15, or 20% (v/v) of chicken or quail egg yolk. The chemical composition of these two eggs was compared. Effects were assessed using an automated analyzer which measured curvilinear velocity (VCL), straight line velocity (VSL), and the velocity of the average path. Linearity was defined as VSL/VCL × 100. The amplitude of the lateral head displacement was also measured. It was found that after the freeze–thaw process, quail egg yolk improved the percentages of motile and progressively undulating spermatozoa and the movement characteristics compared with chicken egg yolk. The optimal concentration of quail egg yolk was 10%. The general composition of the two types of egg yolk were similar, but quail egg yolk contained significantly more phosphatidylcholine, less phosphatidylethanolamine, and a smaller ratio of polyunsaturated to saturated fatty acids than chicken egg yolk. The improvement of motility for frozen–thawed Poitou jackass spermatozoa using frozen–thawed quail egg yolk compared to chicken egg yolk may be due to the differences in composition of the two yolks.     

End-products of enzymic saccharification of beet pulp, with a special attention to feruloylated oligosaccharides

Sugar-beet pulp was hydrolysed by a ‘pectinase’ preparation (‘SP 584’ from Novo Nordisk A/S). High degradation of pectins was observed with release of ~75–85% of the pectic sugars and 70% of the ferulic acid. Of the sugars and ferulic acid initially present in the pulp, ~60–70 and ~40% were released as monomers, respectively. The solubilised material was composed of these monomers and also of some resistant materials, rhamnogalacturonans and feruloylated oligosaccharides. Rhamnogalacturonans, representing only ~5% of the galacturonic and neutral sugars from the pulp, were separated on a Bio-Gel P-4 column eluted by sodium acetate buffer. Two-thirds of these rhamnogalacturonans still carried residual side-chains, the remaining was only constituted of rhamnose and galacturonic acid in a ratio of 1:2. Feruloylated compounds were purified on Sephadex LH-20 and Bio-Gel P-2 columns eluted by water. The main compound was a feruloylated galactobiose, which represented 14% of the initial ferulic acid amount in the pulp. Feruloylated arabinobiose and galactose were also identified, representing only ~3% each of the ferulic acid initially present in pulp.