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Full-Text Articles in Animal Sciences
Intracellular Invasion Of Green Algae In A Salamander Host, Ryan Kerney, Eunsoo Kim, Roger Hangater, Aaron Heiss, Cory Bishop, Brian Hall
Intracellular Invasion Of Green Algae In A Salamander Host, Ryan Kerney, Eunsoo Kim, Roger Hangater, Aaron Heiss, Cory Bishop, Brian Hall
Ryan Kerney
The association between embryos of the spotted salamander (Ambystoma maculatum) and green algae (“Oophila amblystomatis” Lamber ex Printz) has been considered an ectosymbiotic mutualism. We show here, however, that this symbiosis is more intimate than previously reported. A combination of imaging and algal 18S rDNA amplification reveals algal invasion of embryonic salamander tissues and cells during development. Algal cells are detectable from embryonic and larval Stages 26–44 through chlorophyll autofluorescence and algal 18S rDNA amplification. Algal cell ultrastructure indicates both degradation and putative encystment during the process of tissue and cellular invasion. Fewer algal cells were detected in later-stage larvae …
Symbioses Between Salamander Embryos And Green Algae, Ryan Kerney
Symbioses Between Salamander Embryos And Green Algae, Ryan Kerney
Ryan Kerney
The symbiosis between Ambystoma maculatum (spotted salamander) embryos and green algae was initially described over 120 years ago. Algae populate the egg capsules that surround individual A. maculatum embryos, giving the intracapsular fluid a characteristic green hue. Early work established this symbiosis to be a mutualism, while subsequent studies sought to identify the material benefits of this association to both symbiont and host. These studies have shown that salamander embryos benefit from increased oxygen concentrations provided by their symbiotic algae. The algae, in turn, may benefit from ammonia excreted by the embryos. All of these early studies considered the associ- …
Molecular Anatomy Of The Developing Limb In The Coqu ́I Frog, Eleutherodactylus Coqui, Joshua Gross, Ryan Kerney, James Hanken, Clifford Tabin
Molecular Anatomy Of The Developing Limb In The Coqu ́I Frog, Eleutherodactylus Coqui, Joshua Gross, Ryan Kerney, James Hanken, Clifford Tabin
Ryan Kerney
The vertebrate limb demonstrates remark- able similarity in basic organization across phylogenetically disparate groups. To gain further insight into how this mor- phological similarity is maintained in different developmental contexts, we explored the molecular anatomy of size-reduced embryos of the Puerto Rican coqu ́ı frog, Eleutherodactylus coqui. This animal demonstrates direct development, a life- history strategy marked by rapid progression from egg to adult and absence of a free-living, aquatic larva. Nonethe- less, coqu ́ı exhibits a basal anuran limb structure, with four toes on the forelimb and five toes on the hind limb. We in- vestigated the extent to …
Levels Of Biological Organization And The Origin Of Novelty, Brian Hall, Ryan Kerney
Levels Of Biological Organization And The Origin Of Novelty, Brian Hall, Ryan Kerney
Ryan Kerney
The concept of novelty in evolutionary biology pertains to multiple tiers of biological organization from behavioral and morphological changes to changes at the molecular level. Identifying novel features requires assessments of similarity (homology and homoplasy) of relationships (phylogenetic history) and of shared developmental and genetic pathways or networks. After a brief discussion of how novelty is used in recent literature, we discuss whether the evolutionary approach to homology and homoplasy initially formulated by Lankester in the 19th century informs our understanding of novelty today. We then discuss six examples of morphological features described in the recent literature as novelties, and …
Embryonic Staging Table For A Direct- Developing Salamander, Plethodon Cinereus (Plethodontidae), Ryan Kerney
Embryonic Staging Table For A Direct- Developing Salamander, Plethodon Cinereus (Plethodontidae), Ryan Kerney
Ryan Kerney
This work presents a refined staging table for the direct-developing red-backed salamander Plethodon cinereus, which is based on the incom- plete staging system of James Norman Dent (J Morphol 1942; 71:577– 601). This common species from eastern North America is a member of the species-rich lungless salamander family Plethodontidae. The stag- ing table presented here covers several stages omitted by Dent and reveals novel developmental features of P. cinereus embryos. These include putative Leydig cells and open gill clefts, which are found in lar- vae of metamorphosing species but were previously reported as absent in direct-developing Plethodon. Other features found …