Conditions that influence the response to Fgf during otic placode induction

More than a century ago, several embryologists described sites of hematopoietic activity in the vascular wall of mid-gestation vertebrate embryos, and postulated the transient existence of a blood generating endothelium during ontogeny. This hypothesis gained significant attention in the 1970s when orthotopic transplantation experiments between quail and chick embryos revealed specific vascular areas as the site of the origin of definitive hematopoiesis. However, the vascular origin of hematopoietic precursors remained elusive and controversial for decades. Only recently, multiple experimental approaches have clearly documented that during vertebrate development definitive hematopoietic precursors arise from a subset of vascular endothelial cells. Interestingly, this differentiation is promoted by the intravascular fluid mechanical forces generated by the establishment of blood flow upon the initiation of heartbeat, and it is therefore connected with cardiovascular development in several critical aspects. In this review we present our current understanding of the relationship between vascular and definitive hematopoietic development through an historical analysis of the scientific evidence produced in this area of investigation.     

Identification of main effect and epistatic quantitative trait loci for morphological and yield-related traits in peanut (<Emphasis Type="Italic">Arachis hypogaea</Emphasis> L.)

An effort was made in the present study to identify the main effect and epistatic quantitative trait locus (QTL) for the morphological and yield-related traits in peanut. A recombinant inbred line (RIL) population derived from TAG 24 × GPBD 4 was phenotyped in seven environments at two locations. QTL analysis with available genetic map identified 62 main-effect QTLs (M-QTLs) for ten morphological and yield-related traits with the phenotypic variance explained (PVE) of 3.84–15.06%. Six major QTLs (PVE >?10%) were detected for PLHT, PPP, YPP, and SLNG. Stable M-QTLs appearing in at least two environments were detected for PLHT, LLN, YPP, YKGH, and HSW. Five M-QTLs governed two traits each, and 16 genomic regions showed co-localization of two to four M-QTLs. Intriguingly, a major QTL reported to be linked to rust resistance showed pleiotropic effect for yield-attributing traits like YPP (15.06%, PVE) and SLNG (13.40%, PVE). Of the 24 epistatic interactions identified across the traits, five interactions involved six M-QTLs. Three interactions were additive × additive and remaining two involved QTL × environment (QE) interactions. Only one major M-QTL governing PLHT showed epistatic interaction. Overall, this study identified the major M-QTLs for the important productivity traits and also described the lack of epistatic interactions for majority of them so that they can be conveniently employed in peanut breeding.     

Flavonoids of the Hydrangeaceae Dumortier

Fourteen species representing nine genera of the Hydrangeaceae Dumortier were surveyed for their flavonoid pigments. All taxa exhibited profiles based upon common flavonols. Myricetin was seen in two genera: Jamesia and Decumaria. Jamesia was further distinguished by the absence of kaempferol or its glycosides. A complex array of 3-O-mono-, 3-O-di- and 3-O-triglycosides was observed, although not all species had all levels of glycosylation. Decumaria barbara was unique within the species studied in its possession of 3,7-di- and 3,7-triglycosides. The overall pattern of flavonol glycosides observed for the Hydrangeaceae closely resembles that found in herbaceous genera of Saxifragaceae. The comparatively low frequency of myricetin contrasts with its high occurrence in herbaceous genera.