TY - JOUR

T1 - Germinal development in embryonic rediae of the hemiuroid digenean Bunocotyle progenetica

T2 - an ultrastructural study

AU - Podvyaznaya, Irina M.

AU - Galaktionov, Kirill V.

N1 - Podvyaznaya, I.M., Galaktionov, K.V. Germinal development in embryonic rediae of the hemiuroid digenean Bunocotyle progenetica: an ultrastructural study. Parasitol Res 120, 4001–4012 (2021). https://doi.org/10.1007/s00436-021-07349-8

PY - 2021/12

Y1 - 2021/12

N2 - Embryonic development of reproductive organs in rediae of the digenean Bunocotyle progenetica was studied using transmission electron microscopy. The germinal primordium becomes morphologically distinct in early embryos as a weakly separated cell mass with a forming cavity. It consists of undifferentiated, differentiating, and supporting cells. As embryos develop, the supporting cells form a wall around the enlarging cavity. Other cells of the germinal primordium are incorporated into the wall as solitary cells or as small cell aggregations. Those situated posteriorly give rise to an incipient germinal mass functioning during postembryonic development. Undifferentiated and differentiating cells in the middle and the anterior part of the primordium ensure a considerable growth of the cavity wall, which incorporates solitary germinal cells. In advanced embryonic rediae, these cells mature, cleave, and give rise to germinal balls, which enter the forming brood cavity. In the most mature embryonic rediae, all these early cercarial embryos reside in a brood cavity, which is lined by that time with a syncytium continuous with the supporting tissue of the incipient germinal mass. Based on our results and the literature data, we suggest that the morphogenesis of the reproductive apparatus of the daughter parthenitae in hemiuroid digeneans may be characterized by (1) emergence of an incipient brood cavity within the germinal primordium, (2) formation of the cavity lining from the cells of the germinal primordium, (3) fragmentation and uneven distribution of the germinal material of the germinal primordium around the cavity, and (4) an anticipatory development of some of this germinal material.

AB - Embryonic development of reproductive organs in rediae of the digenean Bunocotyle progenetica was studied using transmission electron microscopy. The germinal primordium becomes morphologically distinct in early embryos as a weakly separated cell mass with a forming cavity. It consists of undifferentiated, differentiating, and supporting cells. As embryos develop, the supporting cells form a wall around the enlarging cavity. Other cells of the germinal primordium are incorporated into the wall as solitary cells or as small cell aggregations. Those situated posteriorly give rise to an incipient germinal mass functioning during postembryonic development. Undifferentiated and differentiating cells in the middle and the anterior part of the primordium ensure a considerable growth of the cavity wall, which incorporates solitary germinal cells. In advanced embryonic rediae, these cells mature, cleave, and give rise to germinal balls, which enter the forming brood cavity. In the most mature embryonic rediae, all these early cercarial embryos reside in a brood cavity, which is lined by that time with a syncytium continuous with the supporting tissue of the incipient germinal mass. Based on our results and the literature data, we suggest that the morphogenesis of the reproductive apparatus of the daughter parthenitae in hemiuroid digeneans may be characterized by (1) emergence of an incipient brood cavity within the germinal primordium, (2) formation of the cavity lining from the cells of the germinal primordium, (3) fragmentation and uneven distribution of the germinal material of the germinal primordium around the cavity, and (4) an anticipatory development of some of this germinal material.

KW - Brood cavity

KW - Embryonic redia

KW - Germinal development

KW - Germinal mass

KW - Hemiuroid digeneans

KW - Ultrastructure

KW - ASEXUAL MULTIPLICATION

KW - TREMATODA

KW - MOLLUSCAN HOST

KW - SPOROCYST

KW - MASS

KW - REPRODUCTION

UR - http://www.scopus.com/inward/record.url?scp=85117933232&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/ab5290fd-f809-36c6-9a63-2b79e3f0f767/

U2 - 10.1007/s00436-021-07349-8

DO - 10.1007/s00436-021-07349-8

M3 - Article

AN - SCOPUS:85117933232

VL - 120

SP - 4001

EP - 4012

JO - Parasitology Research

JF - Parasitology Research

SN - 0932-0113

IS - 12

ER -