A conserved checkpoint monitors meiotic chromosome synapsis in Caenorhabditis elegans

We report the discovery of a checkpoint that monitors synapsis between homologous chromosomes to ensure accurate meiotic segregation. Oocytes containing unsynapsed chromosomes selectively undergo apoptosis even if a germline DNA damage checkpoint is inactivated. This culling mechanism is specifically activated by unsynapsed pairing centers, cis-acting chromosome sites that are also required to promote synapsis in Caenorhabditis elegans. Apoptosis due to synaptic failure also requires the C. elegans homolog of PCH2, a budding yeast pachytene checkpoint gene, which suggests that this surveillance mechanism is widely conserved.     

Effect of seed size on protein and lipid contents,germination and imbibition in true potato seeds

Summary Seeds of an open pollinated crop of potato (Solanum tuberosum L.) TPS-2, cv. Kufri Jyoti, were graded into four sizes. There were significant differences between grades for 100-seed weight, the concentrations of total proteins and ethanol soluble proteins, and total lipids and phospholipids. Large seeds contained higher levels (% dry weight) of total proteins, ethanol soluble proteins and alkali soluble proteins than small seeds and they germinated faster and had the highest percentage of germination. Small seeds had the lowest levels of total lipids, phospholipids and water soluble proteins, the longest water saturation time and the lowest germination.     

Mineral and trace element composition in induced mutants of pigeonpea (Cajanus cajan (L.) millsp.)

In the present investigation several mutants isolated during mutagenic studies of pigeonpea were analysed for Ca, Mg, Fe, Zn, Cu, Mn, Cr, Ni. The results have revealed changes in the concentrations of macro and micro mineral elements in the mutant seed material. These changes in concentrations are attributed to the altered genetic structure; due to mutations, the plant system might have absorbed and stored more or less amounts of the elements in the seeds.