在后生動物細胞分裂的“教科書”模型中（該模型建立在對較大海洋動物細胞和Candida elegans細胞所做的一個世紀(jì)的研究基礎(chǔ)之上）,，有絲分裂紡錘體被假設(shè)引導(dǎo)卵裂溝的位置,。
現(xiàn)在,，以檢驗這一模型是否足以解釋一個較小細胞（果蠅成神經(jīng)細胞）的非對稱分裂過程中的卵裂溝位置為目的的實驗表明,，它是不能的。相反,，一個新的路徑在發(fā)揮作用,，在這個路徑中,，Pins (partner of Inscuteable)極性復(fù)合物將形成卵裂溝的蛋白極化到基底皮層，在這里它們誘導(dǎo)收縮環(huán)形成,。這種獨立于紡錘體的細胞動力學(xué)卵裂溝機制可能與其他高度極化的細胞類型也相關(guān),。（生物谷Bioon.com）
生物谷推薦英文摘要：
Nature doi:10.1038/nature09334
A spindle-independent cleavage furrow positioning pathway
Clemens Cabernard，Kenneth E. Prehoda Chris Q. Doe
The mitotic spindle determines the cleavage furrow site during metazoan cell division1, 2, but whether other mechanisms exist remains unknown. Here we identify a spindle-independent mechanism for cleavage furrow positioning in Drosophila neuroblasts. We show that early and late furrow proteins (Pavarotti, Anillin, and Myosin) are localized to the neuroblast basal cortex at anaphase onset by a Pins cortical polarity pathway, and can induce a basally displaced furrow even in the complete absence of a mitotic spindle. Rotation or displacement of the spindle results in two furrows: an early polarity-induced basal furrow and a later spindle-induced furrow. This spindle-independent cleavage furrow mechanism may be relevant to other highly polarized mitotic cells, such as mammalian neural progenitors.
