Day Thomas C, Márquez-Zacarías Pedro, Bravo Pablo, Pokhrel Aawaz R, MacGillivray Kathryn A, Ratcliff William C, Yunker Peter J
School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
Biophys Rev (Melville). 2022 Jun;3(2):021305. doi: 10.1063/5.0080845. Epub 2022 Jun 1.
The diversity of multicellular organisms is, in large part, due to the fact that multicellularity has independently evolved many times. Nonetheless, multicellular organisms all share a universal biophysical trait: cells are attached to each other. All mechanisms of cellular attachment belong to one of two broad classes; intercellular bonds are either reformable or they are not. Both classes of multicellular assembly are common in nature, having independently evolved dozens of times. In this review, we detail these varied mechanisms as they exist in multicellular organisms. We also discuss the evolutionary implications of different intercellular attachment mechanisms on nascent multicellular organisms. The type of intercellular bond present during early steps in the transition to multicellularity constrains future evolutionary and biophysical dynamics for the lineage, affecting the origin of multicellular life cycles, cell-cell communication, cellular differentiation, and multicellular morphogenesis. The types of intercellular bonds used by multicellular organisms may thus result in some of the most impactful historical constraints on the evolution of multicellularity.
多细胞生物的多样性在很大程度上归因于多细胞性已多次独立进化这一事实。尽管如此，多细胞生物都具有一个普遍的生物物理特征：细胞彼此相连。所有细胞附着机制都属于两大类中的一类；细胞间连接要么是可重塑的，要么不是。这两类多细胞聚集体在自然界中都很常见，各自独立进化了数十次。在这篇综述中，我们详细阐述了这些多细胞生物中存在的不同机制。我们还讨论了不同细胞间附着机制对新生多细胞生物的进化影响。在向多细胞性转变的早期阶段存在的细胞间连接类型限制了该谱系未来的进化和生物物理动态，影响多细胞生命周期的起源、细胞间通讯、细胞分化和多细胞形态发生。因此，多细胞生物所使用的细胞间连接类型可能会对多细胞性的进化产生一些最具影响力的历史限制。
