Download presentation
Presentation is loading. Please wait.
Published byJulius Farmer Modified over 8 years ago
1
Reproduction & Development
3
Amixis Amixis by fragmentation Nemertean may aestivate within a mucous cyst.
4
Alternating Life Cycles Obelia colonial proliferation & gonochoristic amphimixis Marine – no diapause
5
Alternating Life Cycles Hydra – Clonal proliferation & gonochoristic amphimixis Note: diapause as egg (c)
6
Alternating Life Cycles Crustacean apomixis & amphimixis Diapause as diploid embryo in ephippium
7
Alternating Life Cycles Rotifer: apomixis & arrhenotoky Diapause as diploid egg
8
Alternating Life Cycles Bryozoan colonial proliferation, amphimixis or autogamy, & clonal proliferation Diapause as multicellular statoblast
9
Alternating Life Cycles Scyphozoan – Aurelia sp. Clonal proliferation & gonochoristic amphimixis Marine – no diapause
10
Alternating Life Cycles Aphid: apomixis & gonochoristic amphimixis Diapause as diploid egg
11
Parasite Life Cycles Trematode – human lung fluke Gonochoristic amphimixis & Polyembryony at several stages
12
Annelida - Epitoky Some Polychaetes produce bags of gametes for mixis either by conversion of body part or amictic budding Coordinated seasonal release
13
Annelid Mixis Simultaneous Hermaphrodites with cross-fertilization Cocoon formation
14
An Hermaphroditic Reproductive Tract : Pallifera sp. alb = albumin gland, at = atrium, bc = bursa copulatrix, bcp = bursa peduncle, chd = common hermaphroditic duct, fov = free oviduct, ovt = ovotestis, p = penis, spov = spermioviduct, vd = vas deferens copyright 2007 J.W. Atkinson
15
First TEM pictures of sperm entering egg – 1960s by Colwin & Colwin using the polychaete, Hydroides TEM Acrosome reaction – sea urchin, Arbacia
16
Developmental Patterns I
17
Developmental Patterns II
18
Developmental Patterns III Mesoderm formation Coelom formation - enterocoely
19
Unique Development: a triclad turbellarian (some critters don’t fit the patterns)
20
Developmental Control: mosaic vs regulative Determination of cell fate occurs before differentiation Early Experimental Embryology - Dichotomy Mosaic vs Regulative early (determinate egg?) late (Indeterminate egg?) Prospective Potency = prospective fate PP> pf pf laid down in egg pf results from cell interactions elimination of cell – loss of structure elimination of cell –adjustment Protostome vs Deuterostome Later Experimental Work – Breakdown of Dichotomy cell interactions also important localized cytoplasmic factors 4d cell gradients of determinants tissue & organism exceptions Current View: Differences in timing of events & stability of Bauplans, i.e. no longer fits the protostome/deuterostome split
21
Octopus: Direct Development pvm = pervitelline membrane, ar = arm, est = eye stalk, mn = mantel, oc = optic lobe, y = yolk f = funnel
22
Insect Larvae & Metamorphosis Hemimetabolous Incomplete metamorphosis
23
Insect Larvae & Metamorphosis Holometabolous: Complete Metamorphosis
24
Imaginal Discs Nemertea: Pallidium larva
25
Metamorphosis Sea Urchin: Pluteus Larva
26
Metamorphosis Urochordate:
27
Adult Cell Turnover Hydra from stem cells
28
Growth: control in arthropods
29
Drosophila hox gene expression
Similar presentations
© 2024 SlidePlayer.com Inc.
All rights reserved.