Embryogenesis of galls cotton nematode meloidogyne incognita acrita (tylenchida, heteroderidae)

The structure of M.incognita acrita egg does not reveal its polarity. During the fusion of pronuclei, the egg cytoplasm forms a pseudomembrane and small protrusions at the egg surface. The cleavage is almost equal and asynchronous. The first four blastomeres are distributed along the longer egg axis what appears to be characteristic of all Tylenchida. Gastrulation proceeds by means of epiboly. Endo- and mesoderm originate from the common rudiment, blastomere EM at the stage of 4 blastomeres, and are represented by independent blastomeres E and M at the stage of 7 blastomeres. Oesophagus and neural rudiment arise from the ectoderm of the anterior embryonic end. The genital rudiment P4 is separated at the stage of 11 blastomeres.