Nouvelles données micropaléontologiques(Foraminifères planctoniques et petits Foraminifères benthiques) sur le stratotype de l'Aquitanien

The authors study the microfauna of small benthonic and planktonic Foraminifera from the Aquitanian stratotype and of a few exposures in the stratotype vicinity.Benthonic microfauna is rich: more than 150species have been collected; among them Miliolidae mainly belonging to the genera Quinqueloculina and Miliola.Planktonic Foraminifera are much less abundant:only 20 species. They authorize to place the stratotype at the boundary of N4–N5 Blow's zones.The figurations of many species are made withthe scanning electronic microscope.     

Nouvelles données micropaléontologiques(Foraminifères planctoniques et petits Foraminifères benthiques) sur le stratotype bordelais du Burdigalien

The present work deals with the microfauna of small benthonic and planktonic Foraminifera from the Burdigalian stratotype of Aquitaine basin (France) and from a few outcrops in the stratotype vicinity showing the upper or lower boundary of the stratotype.Benthonic fauna is rich: more than 250 species divided in 92 genera have been collected. The most frequent are hyaline Foraminifera (Pararotalia, Elphidium, Asterigerina, Florilus, Virgulopsis, Bolivina). The miocene feature is more pronounced than in the Aquitanian stratotype.Planktonic Foraminifera are much less abundant:only 20 species. However, some of them authorize to place the stratotype (or its equivalent l. s.) in N5 Blow's zone and perhaps in the basel N6 zone.The figurations of many species are made withthe scanning electronic microscope.     

Distribution of Clostridial cry-Like Genes Among Bacillus thuringiensis and Clostridium Strains

The presence of two cry-like genes first identified in Clostridium bifermentans subsp. malaysia CH18 was investigated in Clostridium species including 12 subspecies of Clostridium bifermentans, 13 strains of other members of Clostridia genus, and 13 different subspecies of Bacillus thuringiensis. Oligonucleotides designed to amplify the two toxin genes, cmb71 and cmb72, were used. We found that these genes are present in 80% of the Clostridium bifermentans strains tested and in 8% of the other Clostridium and Bacillus thuringiensis strains. Received: 22 July 1997 / Accepted: 15 October 1997     

Dietary protein restriction during lactation in primiparous sows with different live weights at farrowing: I. Consequences on sow metabolic status and litter growth

The hypothesis that the restriction of dietary protein during lactation has different impacts on sow metabolic status and milk production according to body weight was evaluated. From 5-months of age until farrowing, the gilts were fed to achieve body weights of 180 or 240 kg at farrowing. At this time, 38 sows were assigned to one of three groups: " 180 kg" sows not restricted in dietary protein during lactation (180CP); "180 kg" restricted in protein (180LP), or "240 kg" sows restricted in protein (240LP). Catheters were fitted in the jugular vein of 24 sows and serial blood samples were collected 1 d before and 1 d after weaning. Amongst the protein-restricted animals, heavy sows (240LP) had a smaller appetite than light sows in early lactation, resulting in lower energy and protein intakes in the 240LP than in the 180LP sows. Body protein losses were 8, 11 and 13.5% of calculated body protein mass at farrowing in the 180CP, 180LP and 240LP sows, respectively. At the end of lactation, IGF-I concentrations were lower in the 180LP than in the sows from the other groups, probably because of the uncoupling between GH and IGF-I secretions. Low IGF-I concentrations likely promote lean tissue mobilization. Glucose and insulin profiles suggested an insulin resistance state in the 240LP sows compared with the 180LP sows, which may explain, at least in part, the lower feed intake and body reserve mobilization in these sows. Plasma pre- and post-prandial concentrations of amino acids in late lactation differed among the three treatment groups. Throughout lactation, litters from the 180LP and 240LP sows had a slower growth rate than litters from sows which were not restricted, suggesting that endogenous protein mobilization throughout lactation does not completely compensate for a low protein intake.     

Dietary protein restriction during lactation in primiparous sows with different live weights at farrowing: II. Consequences on reproductive performance and interactions with metabolic status

The hypothesis that the restriction of dietary protein during lactation has different impacts on reproductive performance in light and heavy sows at farrowing was investigated, as well as the relationships between reproductive parameters and sow metabolic data. At farrowing, 38 primiparous sows were assigned to one of three groups: sows weighing 180 kg not restricted in dietary protein during lactation (180CP); sows weighing 180 or 240 kg restricted in protein (180LP and 240LP). Twenty-four sows were catheterized and serial blood samples were collected 1 d before and 1 d after weaning. The sows were inseminated at the first estrus after weaning and slaughtered at d 30 of gestation. Protein restriction reduced the proportion of sows that returned to estrus within 8 d after weaning in the 180LP sows (P < 0.03), but not in the 240LP sows. It also induced a reduction in ovulation rate in the 180LP sows (P < 0.05) and, to a lesser extent, in the 240LP sows (P = 0.12). When the sows were categorized according to return to estrus (WOI < or = 8 or > 8 d), basal and mean concentrations of LH increased after weaning only in sows with a short WOI. Sows with a delayed estrus exhibited a higher ratio of plasma tyrosine to large neutral amino acids (AA, P < 0.01). In conclusion, large body reserves at farrowing buffer, at least in part, the detrimental effect of a strongly negative nitrogen balance on reproduction. We suggest that the alteration of AA profiles induced by dietary protein restriction and body protein loss alters LH secretion via modifications of the neurotransmitters involved in GnRH secretion.     

The doubly phosphorylated form of HPr, HPr(Ser~P)(His-P), is abundant in exponentially growing cells of Streptococcus thermophilus and phosphorylates the lactose transporter LacS as efficiently as HPr(His~P)

In Streptococcus thermophilus, lactose is taken up by LacS, a transporter that comprises a membrane translocator domain and a hydrophilic regulatory domain homologous to the IIA proteins and protein domains of the phosphoenolpyruvate:sugar phosphotransferase system (PTS). The IIA domain of LacS (IIALacS) possesses a histidine residue that can be phosphorylated by HPr(His~P), a protein component of the PTS. However, determination of the cellular levels of the different forms of HPr, namely, HPr, HPr(His~P), HPr(Ser-P), and HPr(Ser-P)(His~P), in exponentially lactose-growing cells revealed that the doubly phosphorylated form of HPr represented 75% and 25% of the total HPr in S. thermophilus ATCC 19258 and S. thermophilus SMQ-301, respectively. Experiments conducted with [32P]PEP and purified recombinant S. thermophilus ATCC 19258 proteins (EI, HPr, and IIALacS) showed that IIALacS was reversibly phosphorylated by HPr(Ser-P)(His~P) at a rate similar to that measured with HPr(His~P). Sequence analysis of the IIALacS protein domains from several S. thermophilus strains indicated that they can be divided into two groups on the basis of their amino acid sequences. The amino acid sequence of IIALacS from group I, to which strain 19258 belongs, differed from that of group II at 11 to 12 positions. To ascertain whether IIALacS from group II could also be phosphorylated by HPr(His~P) and HPr(Ser-P)(His~P), in vitro phosphorylation experiments were conducted with purified proteins from Streptococcus salivarius ATCC 25975, which possesses a IIALacS very similar to group II S. thermophilus IIALacS. The results indicated that S. salivarius IIALacS was phosphorylated by HPr(Ser-P)(His~P) at a higher rate than that observed with HPr(His~P). Our results suggest that the reversible phosphorylation of IIALacS in S. thermophilus is accomplished by HPr(Ser-P)(His~P) as well as by HPr(His~P).