The Experts below are selected from a list of 198 Experts worldwide ranked by ideXlab platform
Patricia J. Holman - One of the best experts on this subject based on the ideXlab platform.
-
Molecular and morphological characterization of a haemogregarine in the alligator snapping turtle, Macrochelys temminckii (Testudines: Chelydridae)
Parasitology Research, 2017Co-Authors: Amer Rasool Alhaboubi, Dana A. Pollard, Patricia J. HolmanAbstract:A severely underweight alligator snapping turtle Macrochelys temminckii Troost in Harlan, 1835, was found near Tyler, Texas, and taken to the Caldwell Zoo. Blood films were submitted to Texas A&M University, College Station, Texas, for morphological and molecular identification of haemogregarine-like inclusions in the red blood cells. Intraerythrocytic Haemogregarina sp. forms were found on microscopic examination at a parasitemia of
-
molecular and morphological characterization of a haemogregarine in the alligator snapping turtle macrochelys temminckii testudines Chelydridae
Parasitology Research, 2017Co-Authors: Amer Rasool Alhaboubi, Dana A. Pollard, Patricia J. HolmanAbstract:A severely underweight alligator snapping turtle Macrochelys temminckii Troost in Harlan, 1835, was found near Tyler, Texas, and taken to the Caldwell Zoo. Blood films were submitted to Texas A&M University, College Station, Texas, for morphological and molecular identification of haemogregarine-like inclusions in the red blood cells. Intraerythrocytic Haemogregarina sp. forms were found on microscopic examination at a parasitemia of <1 %. The morphology and morphometric data for the forms indicate similarity to Haemogregarina macrochelysi n. sp. Telford et al., 2009, previously reported in alligator snapping turtles in Florida and Georgia, but two characteristic stage forms were not shared between H. macrochelysi n. sp. and the parasite found in this report. The haemogregarine 18S ribosomal RNA gene (1555-bp fragment) was amplified and cloned, and five clones sequenced. The sequences were deposited in the NCBI GenBank database. All five showed ∼96 % identity to Haemogregarina balli Paterson and Desser, 1976, Hepatozoon sp., and Hemolivia stellata Petit et al., 1990. A 774-bp segment shared 98-99 % identity with the corresponding Haemogregarina sp. rDNA sequence (KR006985) from Caspian turtles (Mauremys caspica McDowell, 1964) in Iran. A neighbor-joining phylogenetic tree generated from aligned sequences from the clones, 26 hematozoa, Adelina dimidiata Schneider, 1875, and Cryptosporidium serpentis Levine, 1980, revealed the cloned sequences clustered on their own branch within the Haemogregarina spp. clade. No genetic data are available for H. macrochelysi n. sp. at this time, so it remains unclear if this parasite in a Texas alligator snapping turtle is conspecific with H. macrochelysi n. sp.
Amer Rasool Alhaboubi - One of the best experts on this subject based on the ideXlab platform.
-
Molecular and morphological characterization of a haemogregarine in the alligator snapping turtle, Macrochelys temminckii (Testudines: Chelydridae)
Parasitology Research, 2017Co-Authors: Amer Rasool Alhaboubi, Dana A. Pollard, Patricia J. HolmanAbstract:A severely underweight alligator snapping turtle Macrochelys temminckii Troost in Harlan, 1835, was found near Tyler, Texas, and taken to the Caldwell Zoo. Blood films were submitted to Texas A&M University, College Station, Texas, for morphological and molecular identification of haemogregarine-like inclusions in the red blood cells. Intraerythrocytic Haemogregarina sp. forms were found on microscopic examination at a parasitemia of
-
molecular and morphological characterization of a haemogregarine in the alligator snapping turtle macrochelys temminckii testudines Chelydridae
Parasitology Research, 2017Co-Authors: Amer Rasool Alhaboubi, Dana A. Pollard, Patricia J. HolmanAbstract:A severely underweight alligator snapping turtle Macrochelys temminckii Troost in Harlan, 1835, was found near Tyler, Texas, and taken to the Caldwell Zoo. Blood films were submitted to Texas A&M University, College Station, Texas, for morphological and molecular identification of haemogregarine-like inclusions in the red blood cells. Intraerythrocytic Haemogregarina sp. forms were found on microscopic examination at a parasitemia of <1 %. The morphology and morphometric data for the forms indicate similarity to Haemogregarina macrochelysi n. sp. Telford et al., 2009, previously reported in alligator snapping turtles in Florida and Georgia, but two characteristic stage forms were not shared between H. macrochelysi n. sp. and the parasite found in this report. The haemogregarine 18S ribosomal RNA gene (1555-bp fragment) was amplified and cloned, and five clones sequenced. The sequences were deposited in the NCBI GenBank database. All five showed ∼96 % identity to Haemogregarina balli Paterson and Desser, 1976, Hepatozoon sp., and Hemolivia stellata Petit et al., 1990. A 774-bp segment shared 98-99 % identity with the corresponding Haemogregarina sp. rDNA sequence (KR006985) from Caspian turtles (Mauremys caspica McDowell, 1964) in Iran. A neighbor-joining phylogenetic tree generated from aligned sequences from the clones, 26 hematozoa, Adelina dimidiata Schneider, 1875, and Cryptosporidium serpentis Levine, 1980, revealed the cloned sequences clustered on their own branch within the Haemogregarina spp. clade. No genetic data are available for H. macrochelysi n. sp. at this time, so it remains unclear if this parasite in a Texas alligator snapping turtle is conspecific with H. macrochelysi n. sp.
Christopher A Sheil - One of the best experts on this subject based on the ideXlab platform.
-
Formation and ossification of limb elements in Trachemys scripta and a discussion of autopodial elements in turtles.
Zoological science, 2008Co-Authors: Christopher A Sheil, Daniel M. PortikAbstract:Though sequences of formation and ossification of bony elements have been described for many taxa, controversy surrounds the formation of limb elements in turtles. Three hypotheses for patterns of formation of autopodial elements have been proposed, differing primarily in the origin of Distal Carpal/Tarsal 3, the digital arch, and Centrale 4. Patterns of formation and ossification of limb elements are described for Trachemys scripta. These patterns are compared to similar data for representatives of four families of turtles (Cheloniidae, Chelydridae, Emydidae, and Trionychidae). Hypotheses of limb formation are compared in the context of new and published data. Three species (Trachemys scripta, Chrysemys picta, and Chelydra serpentina) suggest that Distal Carpal 3 forms by branching from the ulnare, whereas Distal Carpal 3 may branch from Distal Carpal 4 in Macrochelys temminckii and Chelonia mydas; data from Graptemys nigrinoda, Apalone spinifera, and Eretmochelys imbricata did not provide evidence for the origin of Distal Carpal 3. Centrale 4 was not observed to branch from the ulnare and apparently arises by de-novo condensation. Distal Carpal 4 did not branch from Centrale 4 in any species. Until the developmental origins of Distal Carpal 3 and Centrale 4 are understood, interspecific variation in the origin of these elements remains, and may explain some of the observed differences. Trends of ossification in the fore- and hind limb autopodium also are summarized. Homology of elements in pedal Digit V is discussed, and we suggest that the hooked proximal element of this digit be recognized as Distal Tarsal 5.
-
Reconsideration of skeletal development of Chelydra serpentina (Reptilia: Testudinata: Chelydridae): evidence for intraspecific variation
Journal of Zoology, 2005Co-Authors: Christopher A Sheil, Eli GreenbaumAbstract:Patterns of formation and sequence of ossification of the entire skeleton are described for the snapping turtle Chelydra serpentina, based on new and previously published data. Differences in the sequences of ossification events are described and demonstrate considerable intraspecific variation in these developmental data. The chondrocranium of a late developmental-stage specimen is described and illustrated as baseline data for comparative studies. Patterns of formation and chondrification of forelimb and hind limb elements are generally consistent with those of previous studies; however, conspicuous differences in the patterns of ossification are observed among metapodial and phalangeal elements. In the cranium, patterns of ossification of dermal elements are generally more variable than are those of endochondral elements of the braincase, and as in previous studies, endochondral elements ossify after dermal elements. Documented intraspecific variation in sequence and timing of formation, chondrification, and ossification of skeletal elements should serve as a caveat for those conducting studies of phylogeny, heterochrony, and evolution with these data. Causes of natural and induced variation are discussed briefly.
-
Skeletal development of Macrochelys temminckii (Reptilia: Testudines: Chelydridae).
Journal of Morphology, 2004Co-Authors: Christopher A SheilAbstract:Few descriptions of the development and sequence of chondrification and ossification of the entire skeleton of turtles exist, particularly compared to other groups of reptiles. In this study, the embryonic skeleton and its ontogenesis are described for the Alligator Snapping Turtle, Macrochelys temminckii (Chelydridae). Morphological descriptions utilize cleared and double-stained embryonic specimens and form the basis of comparison of the ontogenesis of the skeleton between this species and its extant sister taxon, Chelydra serpentina. The embryonic chondrocranium, as well as the sequences of formation and ossification of the entire skeleton, are compared between these closely related species, and afford a unique opportunity to examine differences in their patterns of skeletal formation. In M. temminckii, the first elements to ossify (Stage 17) are associated with the dermatocranium and upper jaw, followed by elements of the palate, lower jaw, and long bones of the limbs. In both species the majority of endochondral braincase elements (prootic, opisthotic, supraoccipital, and exoccipital) ossify after the majority of dermal elements of the skull. The sequences of formation of the chondral primordia of the limb elements, as well as ossification of autopodial elements, are generally congruent between these species. J. Morphol. 263:71–106, 2005. © 2004 Wiley-Liss, Inc.
Dana A. Pollard - One of the best experts on this subject based on the ideXlab platform.
-
Molecular and morphological characterization of a haemogregarine in the alligator snapping turtle, Macrochelys temminckii (Testudines: Chelydridae)
Parasitology Research, 2017Co-Authors: Amer Rasool Alhaboubi, Dana A. Pollard, Patricia J. HolmanAbstract:A severely underweight alligator snapping turtle Macrochelys temminckii Troost in Harlan, 1835, was found near Tyler, Texas, and taken to the Caldwell Zoo. Blood films were submitted to Texas A&M University, College Station, Texas, for morphological and molecular identification of haemogregarine-like inclusions in the red blood cells. Intraerythrocytic Haemogregarina sp. forms were found on microscopic examination at a parasitemia of
-
molecular and morphological characterization of a haemogregarine in the alligator snapping turtle macrochelys temminckii testudines Chelydridae
Parasitology Research, 2017Co-Authors: Amer Rasool Alhaboubi, Dana A. Pollard, Patricia J. HolmanAbstract:A severely underweight alligator snapping turtle Macrochelys temminckii Troost in Harlan, 1835, was found near Tyler, Texas, and taken to the Caldwell Zoo. Blood films were submitted to Texas A&M University, College Station, Texas, for morphological and molecular identification of haemogregarine-like inclusions in the red blood cells. Intraerythrocytic Haemogregarina sp. forms were found on microscopic examination at a parasitemia of <1 %. The morphology and morphometric data for the forms indicate similarity to Haemogregarina macrochelysi n. sp. Telford et al., 2009, previously reported in alligator snapping turtles in Florida and Georgia, but two characteristic stage forms were not shared between H. macrochelysi n. sp. and the parasite found in this report. The haemogregarine 18S ribosomal RNA gene (1555-bp fragment) was amplified and cloned, and five clones sequenced. The sequences were deposited in the NCBI GenBank database. All five showed ∼96 % identity to Haemogregarina balli Paterson and Desser, 1976, Hepatozoon sp., and Hemolivia stellata Petit et al., 1990. A 774-bp segment shared 98-99 % identity with the corresponding Haemogregarina sp. rDNA sequence (KR006985) from Caspian turtles (Mauremys caspica McDowell, 1964) in Iran. A neighbor-joining phylogenetic tree generated from aligned sequences from the clones, 26 hematozoa, Adelina dimidiata Schneider, 1875, and Cryptosporidium serpentis Levine, 1980, revealed the cloned sequences clustered on their own branch within the Haemogregarina spp. clade. No genetic data are available for H. macrochelysi n. sp. at this time, so it remains unclear if this parasite in a Texas alligator snapping turtle is conspecific with H. macrochelysi n. sp.
Eli Greenbaum - One of the best experts on this subject based on the ideXlab platform.
-
Reconsideration of skeletal development of Chelydra serpentina (Reptilia: Testudinata: Chelydridae): evidence for intraspecific variation
Journal of Zoology, 2005Co-Authors: Christopher A Sheil, Eli GreenbaumAbstract:Patterns of formation and sequence of ossification of the entire skeleton are described for the snapping turtle Chelydra serpentina, based on new and previously published data. Differences in the sequences of ossification events are described and demonstrate considerable intraspecific variation in these developmental data. The chondrocranium of a late developmental-stage specimen is described and illustrated as baseline data for comparative studies. Patterns of formation and chondrification of forelimb and hind limb elements are generally consistent with those of previous studies; however, conspicuous differences in the patterns of ossification are observed among metapodial and phalangeal elements. In the cranium, patterns of ossification of dermal elements are generally more variable than are those of endochondral elements of the braincase, and as in previous studies, endochondral elements ossify after dermal elements. Documented intraspecific variation in sequence and timing of formation, chondrification, and ossification of skeletal elements should serve as a caveat for those conducting studies of phylogeny, heterochrony, and evolution with these data. Causes of natural and induced variation are discussed briefly.