Phylogenetic analysis of Ganoderma australe complex in a Bornean tropical rainforest and implications for mechanism of coexistence of various phylogenetic types

We hypothesized that different phylogenetic types of the Ganoderma australe complex can coexist and that their coexistence is promoted by resource partitioning among them. Our field survey and phylogenetic analysis revealed six phylogenetic types coexisting within a 3 ha primary forest plot in a Bornean tropical rainforest. Two of the six have been reported previously, whereas the remaining four are new. Fruit bodies of all dominant phylogenetic types appeared more frequently from fresh coarse woody debris than expected. Comparison of resource use patterns between the observed fungal community and the null community did not provide significant evidence of niche partitioning. Although we found high genetic diversity within the plot, the phylogenetic types at the site share resources. Resource partitioning on phylogenetic types of host trees or stochastic processes during colonization of pieces of coarse woody debris might play an important role in forming the community structure of phylogenetic types of G. australe

Spindle checkpoint activation at meiosis I advances anaphase II onset via meiosis-specific APC/C regulation

During mitosis, the spindle assembly checkpoint (SAC) inhibits the Cdc20-activated anaphase-promoting complex/cyclosome (APC/CCdc20), which promotes protein degradation, and delays anaphase onset to ensure accurate chromosome segregation. However, the SAC function in meiotic anaphase regulation is poorly understood. Here, we examined the SAC function in fission yeast meiosis. As in mitosis, a SAC factor, Mad2, delayed anaphase onset via Slp1 (fission yeast Cdc20) when chromosomes attach to the spindle improperly. However, when the SAC delayed anaphase I, the interval between meiosis I and II shortened. Furthermore, anaphase onset was advanced and the SAC effect was reduced at meiosis II. The advancement of anaphase onset depended on a meiosis-specific, Cdc20-related factor, Fzr1/Mfr1, which contributed to anaphase cyclin decline and anaphase onset and was inefficiently inhibited by the SAC. Our findings show that impacts of SAC activation are not confined to a single division at meiosis due to meiosis-specific APC/C regulation, which has probably been evolved for execution of two meiotic divisions

ツインブロック装置装着後の脳活動

ツインブロック装置(TBA)の装着による不快感および下顎の前方移動量の増加が前頭葉前部皮質の活動を上昇させるという仮説を立て、これらを検証した。対象は、II級1類不正咬合の顔貌を有する男性10名(II級群)と正常咬合を有する男性10名(I級群)とした。TBAを装着しない場合と装着して下顎を前方へ0、2、4、6、8mm移動させた場合において、ガム咀嚼を20秒間課し、この間の前頭葉前部皮質における酸化ヘモグロビンレベルを光トポグラフィ装置によって計測した。さらに、視覚的評価スケール(VAS)によって快・不快感を定量化した。その結果、TBAの装着によって酸化ヘモグロビンレベルが両群ともに上昇すること、群間の有意差はないこと、下顎を前方移動させても変化はないことが明らかになった。また、TBAを装着して前方移動させると、VASによって示される不快感は増した