Development and characterization of microsatellite markers of the eastern keelback mullet (Liza affinis).

Twenty-four polymorphic microsatellite loci were isolated and characterized for Liza affinis using a (GT)13-enriched genomic library. The number of alleles per locus ranged from 3 to 9, with a mean number of 6.250. The observed and expected heterozygosities ranged from 0.417 to 1.000 and from 0.550 to 0.861, with an average of 0.859 and 0.779, respectively. Deviation from Hardy-Weinberg proportions was detected at three loci. Evidence of null alleles was found at two loci. These markers will be useful in further studies investigating the genetic variation and population structure of this species, and may provide insights into the maintenance and efficient management of eastern keelback mullet resources.

Development of polymorphic microsatellite loci for a new fish species, Chinese sillago (Sillago sinica).

Sillago sinica is a newly identified species belonging to Sillaginidae, Perciforms, and was found along the coast of China in 2011. In the present study, 81 microsatellite loci were isolated from an enriched genomic library, and 24 positive clones containing microsatellite repeats had adequate flanking sequences for the development of PCR primers. Sixteen of these primers were monomorphic or would not amplify. Eight were polymorphic in an examined population with the number of alleles per locus ranging from 2 to 14. The number of observed and expected heterozygosities per locus varied from 0.125 to 0.958 and from 0.120 to 0.904, respectively. The polymorphism information content ranged from 0.110 to 0.721. All loci conformed to Hardy-Weinberg equilibrium (P > 0.05) after Bonferroni correction. There was no significant linkage disequilibrium between the eight polymorphic loci. These results suggest that these markers may be very useful for the characterization of natural populations of this species.

A cytological study of anther and pollen development in Camellia oleifera.

The plant species Camellia oleifera is an important producer of edible oil in China. However, it suffers from a low fruit-setting rate. This study used high resolution scanning electron microscopy of semi-thin tissue sections to investigate anther development and pollen formation, and to determine whether problems in forming functional pollen cause low seed setting rates. During anther development, cell sizes within the epidermis and end othecium gradually increase, and at the beginning of the microsporocyte phase, the cells become highly vacuolated. The cell walls of the inner wall cells thicken in a ribbon pattern during the later part of the two-cell pollen stage. Middle layer cells become flattened during the later part of the secondary sporogenous cell stage. A tapetum also forms at this stage; the secondary sporogenous cells begin to degrade at the early microspore stage and completely disappear by the time the pollen is mature, thus forming a glandular tapetum. In microsporocyte, cytokinesis occurs simultaneously with microsporocyte meiosis, and a tetrahedral arrangement is present in tetrads. Reproductive cells begin to form at the later stage of microsporogenesis; the nuclei of the reproductive cells are enlarged as the reproductive cells begin to move away from the pollen wall. Two-cell pollen is first formed after reproductive cells have left the pollen wall, and the number of inclusions in the pollen subsequently increases. The pollen matures for 5-8 days before flowering occurs. No pollen abortion phenomena were observed, suggesting that anther development in C. oleifera is normal and that functional pollen are formed.