Host-Shift Speciation Proceeded with Gene Flow in Algae Covering Shells.

AbstractHost shifts represent the advancement of a novel niche and often lead to speciation in symbionts. However, its mechanisms are not well understood. Here, we focused on the alga Pseudocladophora conchopheria growing on the shells of intertidal snails. Previous surveys have shown that the alga has host specificity-only attaching to the shell of Lunella correensis-but we discovered that the alga attaches to the shells of multiple sympatric snails. A genome-wide single-nucleotide polymorphism analysis (MIG-seq) was performed to determine whether host-associated speciation occurred in the algae. As a result, there was no gene flow or limited gene flow among the algae from different hosts, and some algae were genetically differentiated among hosts. In addition, the demographic estimate revealed that speciation with gene flow occurred between the algae from different hosts. Therefore, these results support the idea that host-shift speciation gradually proceeded with gene flow in the algae, providing insight into the early evolution of host shifts.

[Thoracoscopic Right S6b+S8a+S9a Combined Subsegmentectomy for Small-sized Lung Cancer].

A 76-year-old man visited to the hospital with a complaint of cough. The chest computed tomography scan revealed a 20 mm part-solid nodule in the right lower lobe, which was suspected to be an early-stage lung cancer. Since the tumor was located in S8a, and was adjacent to S6b and S9a, thoracoscopic right S 6b+S 8a+S 9a combined subsegmentectomy was performed. Virtual-assisted lung mapping (VAL-MAP) with indocyanine green( ICG) was performed as the preoperative marking. After dissecting the target vessels and bronchi, the intersegmental plane was identified using intravenous ICG. The pathological diagnosis was invasive mucinous adenocarcinoma with no lymph node metastasis. Combined subsegmentectomy is a useful option for the sublober resection of small lung cancer.