Ronderos Jorge R
Centro Regional de Estudios Genómicos (CREG-UNLP) and Cátedra de Histología y Embriología Animal (FCNyM-UNLP) La Plata, Argentina.
Biocell. 2009 Dec;33(3):149-54.
Triatoma infestans, a blood-feeding insect, synchronises physiological mechanisms leading to moult with food intake. Since the corpora allata are important in moult and metamorphosis regulation, we have studied morphological changes in 4th instar nymphs (gland size, cell density, percent of animals showing mitoses and cell size). Changes were correlated with the effect of precocene II, epidermal proliferation, and with the extent of the "head critical period". Based on morphological grounds, three stages can be defined in the gland along the 4th instar: Stage 1 (days 0-2 after feeding) showed small corpora allata, composed by a small number of cells, and in which mitoses were absent; Stage 2 (days 3-9) showed growing corpora allata, in which cell number was increasing and proliferation was apparent; and Stage 3 (days 10-13) showed no mitotic activity, and a sharply diminishing size of the gland, as a consequence of the diminishing size of their cells. The ability of precocene II to induce abnormal moulting disappeared during stage 2 correlating with the termination of the head critical period and suggesting that corpora allata are essential during days 3 to 5 to determine normal growth. Epidermal cell number was increasing as a consequence of more frequent mitotic activity, beginning after the finalization of the head critical period and after a first increment in the size of the gland.
骚扰锥蝽是一种吸血昆虫，它会使导致蜕皮的生理机制与食物摄入同步。由于咽侧体在蜕皮和变态调节中起着重要作用，我们研究了四龄若虫的形态变化（腺体大小、细胞密度、有丝分裂的动物百分比和细胞大小）。这些变化与早熟素II的作用、表皮增殖以及“头部关键期”的时长相关。基于形态学依据，在四龄若虫阶段，腺体可分为三个阶段：第一阶段（进食后0 - 2天），咽侧体较小，由少量细胞组成，无有丝分裂现象；第二阶段（3 - 9天），咽侧体生长，细胞数量增加且增殖明显；第三阶段（10 - 13天），无有丝分裂活动，由于细胞大小减小，腺体大小急剧缩小。早熟素II诱导异常蜕皮的能力在第二阶段消失，这与头部关键期的结束相关，表明咽侧体在第3至5天对于决定正常生长至关重要。表皮细胞数量因有丝分裂活动更频繁而增加，这在头部关键期结束后以及腺体大小首次增加后开始。
