[Show abstract][Hide abstract] ABSTRACT: We have analysed the distribution of post mortem DNA damage derived miscoding lesions from the datasets of seven published Neandertal specimens that have extensive cloned sequence coverage over the mitochondrial DNA (mtDNA) hypervariable region 1 (HVS1). The analysis was restricted to C-->T and G-->A miscoding lesions (the predominant manifestation of post mortem damage) that are seen at a frequency of more than one clone among sequences from a single PCR, but do not represent the true endogenous sequence.
The data indicates an extreme bias towards C-->T over G-->A miscoding lesions (observed ratio of 67:2 compared to an expected ratio of 7:2), implying that the mtDNA Light strand molecule suffers proportionally more damage-derived miscoding lesions than the Heavy strand.
The clustering of Cs in the Light strand as opposed to the singleton pattern of Cs in the Heavy strand could explain the observed bias, a phenomenon that could be further tested with non-PCR based approaches. The characterization of the HVS1 hotspots will be of use to future Neandertal mtDNA studies, with specific regards to assessing the authenticity of new positions previously unknown to be polymorphic.
[Show abstract][Hide abstract] ABSTRACT: Reptiles are typical capital breeders that fuel reproduction by the use of lipids stored in fat bodies. However, little is known about the origin (exogenous or endogenous) of egg protein. We have examined the origin of egg protein by means of the analysis of protein content of liver and carcass (skeletal muscle) of the oviparous snake Natrix maura throughout an annual cycle. We have also measured monthly variation of the digestive-content mass and the ovarian mass. Results showed that protein in liver peaked during vitellogenesis according to the role of the liver in the synthesis of vitellogenin. Partial correlations showed the path of protein from the prey (digestive-content) to the liver, and finally to the ovaries, as well as an inverse relation between carcass protein and ovarian mass. Carcass muscle is the only body part that may act as a potential reserve for endogenous protein, although we did not find significant variation in carcass protein during female reproduction. As females with large follicles did not stop foraging activity, we assumed that egg protein was derived from the diet as partial correlations indicated. Our results suggest that N. maura is a capital breeder for lipids and tend to be income breeder for protein. This conclusion contrasts with that observed in capital breeders for which egg protein was derived from muscle. We discuss the idea that flexibility in the origin of egg protein could affect the body condition in post-reproductive females.
Comparative Biochemistry and Physiology - Part A Molecular & Integrative Physiology 06/2007; 147(1):165-72. · 2.17 Impact Factor