TY - JOUR

T1 - Colonial system of integration and communication pores in a polymorphic bryozoan Dendrobeania fruticosa (Bryozoa: Cheilostomata)

AU - Шунатова, Наталья Николаевна

AU - Денисова, Софья Александровна

AU - Щенков, Сергей Владимирович

AU - Филиппов, Артем Игоревич

PY - 2023/5/26

Y1 - 2023/5/26

N2 - Bryozoan colonies are composed of zooids, which can differ in structure andfunction. Autozooids supply heteromorphic zooids with nutrients, which are usuallyunable to feed. To date, the ultrastructure of the tissues providing nutrient transferis almost unexplored. Here, we present a detailed description of the colonial systemof integration (CSI) and the different types of pore plates in Dendrobeania fruticosa.All cells of the CSI are joined by tight junctions that isolate its lumen. The lumen ofthe CSI is not a single structure, but a dense network of small interstices filled with aheterogeneous matrix. In autozooids, the CSI is composed of two types of cells:elongated and stellate. Elongated cells form the central part of the CSI, including twomain longitudinal cords and several main branches to the gut and pore plates.Stellate cells compose the peripheral part of the CSI, which is a delicate meshstarting from the central part and reaching various structures of autozooids.Autozooids have two tiny muscular funiculi, which start from the caecum apex andrun to the basal wall. Each funiculus includes a central cord of extracellular matrixand two longitudinal muscle cells; together they are enveloped with a layer of cells.The rosette complexes of all types of pore plates in D. fruticosa display a similarcellular composition: a cincture cell and a few special cells; limiting cells are absent.Special cells have bidirectional polarity in interautozooidal and avicularian poreplates. This is probably due to the need for bidirectional transport of nutrients duringdegeneration–regeneration cycles. Cincture cells and epidermal cells of pore platescontain microtubules and inclusions resembling dense‐cored vesicles, which aretypical of neurons. Probably, cincture cells are involved in the signal transductionfrom one zooid to another and can be a part of the colony‐wide nervous system.

AB - Bryozoan colonies are composed of zooids, which can differ in structure andfunction. Autozooids supply heteromorphic zooids with nutrients, which are usuallyunable to feed. To date, the ultrastructure of the tissues providing nutrient transferis almost unexplored. Here, we present a detailed description of the colonial systemof integration (CSI) and the different types of pore plates in Dendrobeania fruticosa.All cells of the CSI are joined by tight junctions that isolate its lumen. The lumen ofthe CSI is not a single structure, but a dense network of small interstices filled with aheterogeneous matrix. In autozooids, the CSI is composed of two types of cells:elongated and stellate. Elongated cells form the central part of the CSI, including twomain longitudinal cords and several main branches to the gut and pore plates.Stellate cells compose the peripheral part of the CSI, which is a delicate meshstarting from the central part and reaching various structures of autozooids.Autozooids have two tiny muscular funiculi, which start from the caecum apex andrun to the basal wall. Each funiculus includes a central cord of extracellular matrixand two longitudinal muscle cells; together they are enveloped with a layer of cells.The rosette complexes of all types of pore plates in D. fruticosa display a similarcellular composition: a cincture cell and a few special cells; limiting cells are absent.Special cells have bidirectional polarity in interautozooidal and avicularian poreplates. This is probably due to the need for bidirectional transport of nutrients duringdegeneration–regeneration cycles. Cincture cells and epidermal cells of pore platescontain microtubules and inclusions resembling dense‐cored vesicles, which aretypical of neurons. Probably, cincture cells are involved in the signal transductionfrom one zooid to another and can be a part of the colony‐wide nervous system.

KW - Autozooid

KW - avicularium

KW - funicular system

KW - funiculus

KW - kenozooid

KW - rosette complexes

KW - ultrastructure

UR - https://www.mendeley.com/catalogue/f2cba53c-d013-39af-a63b-d9822ee40581/

U2 - 10.1002/jmor.21601

DO - 10.1002/jmor.21601

M3 - Article

VL - 284

JO - Journal of Morphology

JF - Journal of Morphology

SN - 0362-2525

IS - 7

M1 - e21601

ER -