Origin and Structure of a Large Aggregation of Suwannee Cooters (Pseudemys concinna suwanniensis) in a Florida Spring

We have cloned a developmentally regulated mitogen-activated protein kinase (extracellular signal-regulated kinase) from Dictyostelium discoideum designated ERK1. Using anti-pTyr antibodies, we show that ERK1 is phosphorylated on tyrosine in vivo and that it will phosphorylate myelin basic protein. The gene expresses two transcripts, one that is preferentially expressed during vegetative growth and early development and one that is induced during the multicellular stages. Developmental Western blots (immunoblots) using anti-ERK1 antibodies indicate that ERK1 is present throughout development. ERK1/lacZ reporter constructs suggest that, in the multicellular stages, the gene is preferentially expressed in a subpopulation of cells scattered throughout the organism, similar to the pattern seen with anterior-like cell markers. Antisense mutagenesis from a derepressible promoter indicates that ERK1 is essential for vegetative growth. Overexpression of ERK1 from either the Actin 15 promoter or the ERK1 promoter results in abnormal morphogenesis starting at the slug stage. Overexpression of ERK1 in null mutants of the phosphotyrosine phosphatase PTP2 results in the production of large aggregation streams and subsequent abnormal morphogenesis that indicate a genetic interaction between ERK1 and PTP2. These cells produce very large aggregation streams that break up into very small mounds that undergo abnormal morphogenesis. The genetic interaction between ERK1 and PTP2 appears to be specific since overexpression of ERK1 in a ptp1- null mutant does not produce the same phenotype. Our results indicate that ERK1 plays an essential role during the growth and differentiation of D. discoideum.

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Termite colonies from mid-Cretaceous Myanmar demonstrate their early eusocial lifestyle in damp wood

National Science Review ◽

10.1093/nsr/nwz141 ◽

2019 ◽

Vol 7 (2) ◽

pp. 381-390 ◽

Cited By ~ 12

Author(s):

Zhipeng Zhao ◽

Xiangchu Yin ◽

Chungkun Shih ◽

Taiping Gao ◽

Dong Ren

Keyword(s):

Overlapping Generations ◽

Division Of Labour ◽

Brood Care ◽

Burmese Amber ◽

Multiple Generations ◽

Large Aggregation ◽

Rotting Wood ◽

Reproductive Division Of Labour ◽

Reproductive Division

Abstract Insect eusociality is characterized by cooperative brood care, reproductive division of labour and multiple generations of adults within a colony. The morphological specializations of the different termite castes from Burmese amber were recently reported, indicating the termites possessed advanced sociality in the mid-Cretaceous. Unfortunately, all the reported Cretaceous termites are individually preserved, which does not cover the behaviours of the cooperative brood care and multiple generations of adults in the nests of the Cretaceous termites. Herein, we report three eusocial aggregations from colonies of the oldest known Stolotermitidae, Cosmotermesgen. nov., in 100 Ma mid-Cretaceous Burmese amber. One large aggregation, comprising 8 soldiers, 56 workers/pseudergates and 25 immatures of different instars, additionally presents the behaviours of cooperative brood care and overlapping generations. Furthermore, taphonomic evidence indicates Cosmotermes most probably dwelled in damp/rotting wood, which provides a broader horizon of the early societies and ecology of the eusocial Cosmotermes.

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