Tetrapioid induction of Crassostrea hongkongensis and C.sikamea by inhibiting the polar body 1 release in diploid fertilized eggs

The production of an all-triploid population by mating tetrapioid males with diploid females is the best and most fundamental method for the large-scale production of triploid oysters.Obtaining a stable tetrapioid population is essential for guaranteed production in industrialized triploid cultivation.C.hongkongensis and C.sikamea are important oyster breeding species in southern China,and have great economic value.However,there are not any published data on inducing tetrapioid C.hongkongensis or C.sikamea.Therefore,we investigated tetrapioid induction in these two oyster species by inhibiting the PB1 release in diploid fertilized eggs using Cytochalasin B(CB)under 31℃,15%o salinity.The results confirmed that the optimal tetrapioid induction conditions for C.hongkongensis were a CB concentration of 0.50 mg/L with induction starting at 9.0 min after fertilization,and stopping at 21.0 min after fertilization;the induction efficiency index reached 0.123 under these conditions.The optimal tetrapioid induction conditions for C.sikamea were a CB concentration of 0.50 mg/L,with induction starting at 7.5 min after fertilization and stopping at 18 min after fertilization;the induction efficiency index could be as high as 0.281 under these conditions.However,we confirmed that the tetrapioid rate decreased with larval growth,and no tetrapioids were detected in the juvenile period of either C.hongkongensis or C.sikamea.This may be attributed to the very low survival of the tetrapioid larvae induced by this method,especially as most tetrapioid larvae died during the first three days.In summary,it is simple to directly induce tetrapioid C.hongkongensis and C.sikamea larvae by inhibiting the PB1 release of diploid zygotes,but the low survival rate makes it challenging to obtain viable juvenile tetrapioids.

The Inductive Blockwise Alperin Weight Condition for PSL（3, q）

The blockwise Alperin weight conjecture assets that for any finite group G and any prime l, the number of the Brauer characters in an l-block B equals the number of the G-conjugacy classes of l-weights belonging to B. Recently, the inductive blockwise Alperin weight condition has been introduced such that the blockwise Alperin weight conjecture holds if all non-abelian simple groups satisfy these conditions. We will verify the inductive blockwise Alperin weight condition for the finite simple groups PSL（3, q） in this paper.

The McKay Conjecture for Finite Groups with Abelian Sylow 3-Subgroups

In this paper, we prove that the McKay conjecture holds for finite groups with abelian Sylow 3-subgroups and any prime l via the inductive McKay condition.2010 Mathematics Subject Classification： 20C15, 20C33