Genetic studies on seedling vigour in sesame

Genetic studies were carried out on seedling and agronomic characters amongst 50 sesame genotypes to estimate the genetic variation, determine the relationships amongst the characters and identify rapidly growing genotypes with vigorous seedling growth. The contribution of genetic variance was highest for the two mature characters, days to first flower (95.6%) and number of nodes to first flower (95.2%), and was medium/high (50–75%) for most of the seedling characters. Strong positive genetic correlations were obtained between various cotyledon and early leaf characteristics measured at 20 days after sowing. Based on these results several genotypes were identified as having rapid seedling growth and these could form an initial gene pool to provide material for screening for tolerance to sesame flea beetle.     

Evolutionary relationships among hares from North Africa (Lepus sp. or Lepus spp.), cape hares (L. capensis) from South Africa, and brown hares (L. europaeus), as inferred from mtDNA PCR-RFLP and allozyme data

Systematics and taxonomy of hares of the genus Lepus (Lagomorpha) are under contentious debate, and phylogenetic relationships among many taxa are not well understood. Here we study genetic differentiation and evolutionary relationships among North African hares, currently considered subspecies of Lepus capensis , cape hares ( L. capensis ) from the Cape province in South Africa, and brown hares ( L. europeaus ) from Europe and Anatolia, using maternally (mtDNA) and biparentally (allozymes) inherited markers. A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of a c. 1.8 kb long segment of the mitochondrial control region using eight hexanucleotide-recognizing restriction endonucleases yielded 28 haplotypes, and horizontal starch gel electrophoresis of proteins encoded by 25 structural gene loci revealed 52 alleles at 18 polymorphic loci. Diverse phylogenetic analyses (neighbor joining dendrogram, median joining network, multidimensional scaling of pairwise distances, AMOVA, F -statistics, hierarchical F -statistics) of genetic variants revealed marked substructuring of mtDNA into three phylogeographic groups, namely an African, a central European, and an Anatolian, but a somewhat less pronounced overall differentiation of the nuclear genome, despite a relatively high number of population-specific (private) alleles. However, all our results are not incongruent with Petter's (1959: Mammalia 23 , 41; 1961: Z. f. Säugetierkunde 26 , 30; 1972 : Société Des Sciences Naturelles et Physiques du Maroc 52 , 122) hypothesis that North African hares generally belong to L. capensis and that brown hares should be included in this species as well.     

Maternal or fetal origin of rhesus monkey (Macaca mulatta) amniotic fluid leukocytes can be identified by polymerase chain reaction using the zinc finger Y gene.

Leukocytes can be found in substantial numbers within the intrauterine tissues and amniotic fluid of women, and play a central role in the pathophysiology of infection-related preterm labor by their production of proinflammatory mediators. It remains unclear whether these leukocytes represent a fetal immune response, a maternal response, or a combination of the two. The objective of this study was to develop a test in the rhesus monkey (Macaca mulatta) suitable for determining the percentage of male fetal cells present in a population of leukocytes recovered from blood or amniotic fluid. We found inadequate specificity for rhesus monkey cells using commercial human Y-chromosome paint kits (fluorescence in situ hybridization (FISH)). Human-specific primers for the repetitive Y chromosome DYZ-1 locus employed in the polymerase chain reaction (PCR) produced an unacceptable percentage of false positives. However, we successfully developed a PCR-based test using rhesus-specific primers for the zinc finger Y (ZFY) locus. Densitometry of PCR products from known ratios of male and female adult peripheral leukocytes generated a linear standard curve which provided quantitative results and required only 400 cells per sample. The rhesus beta globin (RBG) gene served as an internal control. The PCR test correctly discriminated the sex of peripheral leukocytes in 20 adult males, 20 adult females, two male fetuses, and one female fetus. Serial samples of amniotic fluid from four chronically catheterized rhesus monkeys bearing male fetuses were used to confirm the utility of this assay for quantifying fetal cells in amniotic fluid. In conclusion, we have developed a PCR test which is suitable for distinguishing male from female cells in adult and fetal blood and in amniotic fluid, which lends itself to a variety of diagnostic and biologic applications in the rhesus monkey and potentially in other nonhuman primates.     

Don C. Ohadike: The Man, his Intellectual Legacy and African Historiography

It is difficult to completely understand the life history of an intellectual excluding an understanding of his family upbringing and formative years. Family upbringing and childhood environment, often the less known part of a life history, play crucial roles in shaping the ideas and values individuals espouse in their adult life. Notwithstanding, this paper is not concerned with Don C. Ohadike’s childhood. It rather focuses on the professional career of our able historian – that is the part of his life as revealed by his most outstanding published writings. Ohadike’s published works contain a wellspring of idioms that tell much about his values, quality of mind, and his mission as an African historian. Ohadike was a humanist, an African patriot, and a nationalist crusader. His entire philosophy centered on safeguarding his African identity in an emergent world of cultural imperialism. The funds for this research were provided by a NEH-funded fellowship at the Schomburg Center, New York in the Spring of 2007. I owe a lot of gratitude to Professor John McLeod and Dean Blaine Hudson for granting me the extra incentives to pursue my research in New York. While all errors and misinterpretations are mine, I wish to thank the editors and anonymous reviewers for Journal of Dialectical Anthropology for their perspective comments and suggestions on earlier drafts of this paper.     

Latency of Botrytis cinerea Pers.: Fr. and Biochemical Studies During Growth and Ripening of Two Grape Berry Cultivars, Respectively Susceptible and Resistant to Grey Mould

Latency and development of Botrytis cinerea were assessed under field conditions and after artificial inoculation of two grape varieties, Gamay (susceptible) and Gamaret (resistant). When the percentage of latent Botrytis was the same for both varieties, severity of visible grey mould remained very low in Gamaret berries, while Gamay clusters were destroyed by the disease to a high percentage. Some biochemical parameters were measured in berries, such as constitutive and induced anti‐fungal compounds, polymeric proanthocyanidins and lipid peroxidation products as markers of senescence. Differences were observed in polymeric proanthocyanidins (PPRA) of Gamaret compared with those of Gamay. Concentration and mean degree of polymerization (mDP) of PPRA were always higher in the berries of the resistant variety. The inhibitory effect of Gamaret PPRA on enzyme activity remained until harvest whereas Gamay PPRA lost their inhibitory activity at the beginning of véraison. Based on these results, resistance to B. cinerea seems to be linked to the maintainance of the fungus in its latent form in berries, mainly due to the ability of Gamaret PPRA to inhibit macerating fungal enzyme activities.     

Neuropeptide gene expression and neural activity: Assessing a working hypothesis in nucleus caudalis and dorsal horn neurons expressing preproenkephalin and preprodynorphin

1. The working hypothesis that neuropeptide gene expression in a neuron is an indicator of that neuron's physiological activity is discussed. 2. Representative examples from the literature are presented to support the hypothesis. 3. Further, we discuss the regulation of expression of two opioid peptides, preproenkephalin and preprodynorphin, in laminae I and II of the spinal cord and in nucleus caudalis of the trigeminal nuclear complex, where they may play a role in pain modulation. 4. The expression of the opioid peptide genes can be induced by both painful and nonnoxious stimuli in neurons in time-dependent and sensory-specific fashions.     

Lectin-gene expression in pea (Pisum sativum L.) roots

The expression of a lectin gene in pea (Pisum sativum L.) roots has been investigated using the copy DNA of a pea seed lectin as a probe. An mRNA which has the same size as the seed mRNA but which is about 4000 times less abundant has been detected in 21-d-old roots. The probe detected lectin expression as early as 4 d after sowing, with the highest level being reached at 10 d, i.e. just before nodulation. In later stages (16-d- and 21-d-old roots), expression was substantially decreased. The correlation between infection by Rhizobium leguminosarum and lectin expression in pea roots has been investigated by comparing root lectin mRNA levels in inoculated plants and in plants grown under conditions preventing nodulation. Neither growth in a nitrate concentration which inhibited nodulation nor growth in the absence of Rhizobium appreciably affected lectin expression in roots.Abbreviation cDNA copy DNA - poly(A)⁺RNA polyadenylated RNA