The Xerobranching Response Represses Lateral Root Formation When Roots Are Not in Contact with Water

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Protein metabolism in the newborn lamb. IV. Consequences of amino acid and lactose ingestion

A study was made on protein metabolism and hormonal changes following birth in newborn lambs fed amino acids alone or in combination with lactose. Eight newborn lambs taken from their mother immediately after birth were fed hourly for 8 h, either with a solution of peptides and free amino acids obtained by mild hydrolysis of whey proteins (4 lambs; diet AP) or with the same solution + lactose (4 lambs; diet APL). L-[4,5-3H] leucine was continuously perfused into a jugular vein for 6 h when the lambs were 2 h 30 min old. Plasma glucose and insulin levels increased after birth in APL lambs whereas they decreased in the AP; these differences were significantly different. Plasma cortisol levels remained unchanged throughout the experiment. Free essential amino acid levels did not vary when lambs were older than 4.5 h; they depended on the corresponding amino acid intakes. Plasma free threonine, valine, isoleucine, leucine, tyrosine and lysine were lower in APL than in AP lambs. The plasma leucine irreversible loss and leucine oxidation were higher in AP than in APL lambs. The plasma flux of leucine from whole body protein breakdown was lower in APL than in AP lambs inasmuch as the plasma flux of dietary leucine may be estimated by the amounts of leucine ingested in both cases. No significant difference was found for the fractional synthesis rates of tissue proteins such as liver, skin, skeletal muscle, lung, brain and whole body. These rates for skin, muscle and whole body were close to those previously measured in colostrum fed lambs. The increase in whole body protein accretion resulting from lactose feeding in combination with amino acids seemed to result from a decreased protein breakdown that could be mediated by the insulin response.     

Genome sequence of Micromonospora lupini Lupac 08, isolated from root nodules of Lupinus angustifolius

Micromonospora strains have been isolated from diverse niches, including soil, water, and marine sediments and root nodules of diverse symbiotic plants. In this work, we report the genome sequence of Micromonospora lupini Lupac 08 isolated from root nodules of the wild legume Lupinus angustifolious.     

Immature hematopoietic stem cells undergo maturation in the fetal liver

Hematopoietic stem cells (HSCs), which are defined by their capacity to reconstitute adult conventional mice, are first found in the dorsal aorta after 10.5 days post coitus (dpc) and in the fetal liver at 11 dpc. However, lympho-myeloid hematopoietic progenitors are detected in the dorsal aorta from 9 dpc, raising the issue of their role in establishing adult hematopoiesis. Here, we show that these progenitors are endowed with long-term reconstitution capacity, but only engraft natural killer (NK)-deficient Rag2γc(-/-) mice. This novel population, called here immature HSCs, evolves in culture with thrombopoietin and stromal cells, into HSCs, defined by acquisition of CD45 and MHC-1 expression and by the capacity to reconstitute NK-competent mice. This evolution occurs during ontogeny, as early colonization of fetal liver by immature HSCs precedes that of HSCs. Moreover, organ culture experiments show that immature HSCs acquire, in this environment, the features of HSCs.     

Xenopus Meiotic Microtubule-Associated Interactome

In metazoan oocytes the assembly of a microtubule-based spindle depends on the activity of a large number of accessory non-tubulin proteins, many of which remain unknown. In this work we isolated the microtubule-bound proteins from Xenopus eggs. Using mass spectrometry we identified 318 proteins, only 43 of which are known to bind microtubules. To integrate our results, we compiled for the first time a network of the meiotic microtubule-related interactome. The map reveals numerous interactions between spindle microtubules and the newly identified non-tubulin spindle components and highlights proteins absent from the mitotic spindle proteome. To validate newly identified spindle components, we expressed as GFP-fusions nine proteins identified by us and for first time demonstrated that Mgc68500, Loc398535, Nif3l1bp1/THOC7, LSM14A/RAP55A, TSGA14/CEP41, Mgc80361 and Mgc81475 are associated with spindles in egg extracts or in somatic cells. Furthermore, we showed that transfection of HeLa cells with siRNAs, corresponding to the human orthologue of Mgc81475 dramatically perturbs spindle formation in HeLa cells. These results show that our approach to the identification of the Xenopus microtubule-associated proteome yielded bona fide factors with a role in spindle assembly.     

The C system of cattle blood groups. 1. Additional factors in the system

Four additional cattle blood group antigenic factors, provisionally termed F1, F6, F10 and F15, were shown to belong to the C system. Factor F1 appears to be a linear subtype of C" (initially designated F2, or P1B1). It is suggested that future international nomenclature should adopt C"1 and C"2 in place of F1 and C". No phenogroup was found to include C" together with C2 or C1, but a few phenogroups lack the three factors. Thus C1, C2 and C" do not form a closed system within the C system as concluded by Duniec et al. (1973). The effectiveness of the additional factors to uncover the genetic variability of the C system, and to translate phenotypes into genotypes is exemplified in the Charolais breed.