Abstract：
:Features of embryonic development in birds traditionally have been assumed to be shared by sauropsids in general. Herein, we document a pattern of yolk processing and cellularization in the Eastern fence lizard (Sceloporus undulatus) that is fundamentally different from that of birds. In the avian pattern, cells of the yolk sac lining phagocytose, and digest yolk material. These cells release products of digestion into underlying blood vessels for transport back to the embryo. In contrast, microscopic examination of the developing eggs of S. undulatus reveals that the yolk mass is converted into vascularized, "spaghetti-like" strands that fill the yolk sac cavity. Three successive developmental stages are involved. First, the liquid yolk is invaded by proliferating endodermal cells, which phagocytose and digest the yolk material. These cells form clumps that progressively fill the yolk sac cavity. Second, small blood vessels derived from the yolk sac vasculature invade the yolk sac cavity. Third, the endodermal cells become organized in monolayers around these vessels. This arrangement provides a means by which large numbers of endodermal cells can digest yolk, with each cell being positioned to release products of digestion into an adjacent blood vessel for transport to the embryo. The mechanism of yolk processing in this lizard species is similar to that of recently studied snakes. From its phylogenetic distribution, we infer that this pattern probably is ancestral for squamate sauropsids.
journal_name
J Morpholjournal_title
Journal of morphologyauthors
Blackburn DG,Lestz L,Barnes MS,Powers KG,Langkilde Tdoi
10.1002/jmor.20892subject
Has Abstractpub_date
2018-11-01 00:00:00pages
1629-1639issue
11eissn
0362-2525issn
1097-4687journal_volume
279pub_type
杂志文章abstract：:The oval olfactory rosette of the carp Labeo rohita belongs to Burne's ('09) rosette column one or to Bateson's (1889) rosette type three. The total olfactory area of the fish is greater than its total retinal area; however, it has been classified with Teichmann's ('54) group of eye-nose fishes. Each olfactory chamber...
journal_title：Journal of morphology
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doi：10.1002/jmor.1051400107
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journal_title：Journal of morphology
pub_type： 杂志文章
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abstract：:Several muroid rodent species are distributed throughout southern Africa. Some species are reportedly classified as opportunistic omnivorous rodents consuming plant, seed, and insect material. This study aims to provide a detailed morphometric analysis of the gastrointestinal tract (GIT) of four such omnivorous specie...
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journal_title：Journal of morphology
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journal_title：Journal of morphology
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journal_title：Journal of morphology
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journal_title：Journal of morphology
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journal_title：Journal of morphology
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更新日期：2002-05-01 00:00:00
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journal_title：Journal of morphology
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更新日期：1999-09-01 00:00:00
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journal_title：Journal of morphology
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journal_title：Journal of morphology
pub_type： 杂志文章
doi：10.1002/jmor.10592
更新日期：2008-03-01 00:00:00
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journal_title：Journal of morphology
pub_type： 杂志文章
doi：10.1002/jmor.10816
更新日期：2010-05-01 00:00:00
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journal_title：Journal of morphology
pub_type： 杂志文章
doi：10.1002/(SICI)1097-4687(199903)239:3<271::AID-JMOR
更新日期：1999-03-01 00:00:00
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journal_title：Journal of morphology
pub_type： 杂志文章
doi：10.1002/jmor.20396
更新日期：2015-09-01 00:00:00
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journal_title：Journal of morphology
pub_type： 杂志文章
doi：10.1002/jmor.1052160102
更新日期：1993-04-01 00:00:00
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journal_title：Journal of morphology
pub_type： 杂志文章
doi：10.1002/jmor.10202
更新日期：2005-05-01 00:00:00
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journal_title：Journal of morphology
pub_type： 杂志文章
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更新日期：2013-09-01 00:00:00
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journal_title：Journal of morphology
pub_type： 杂志文章
doi：10.1002/(SICI)1097-4687(200003)243:3<247::AID-JMOR
更新日期：2000-03-01 00:00:00
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journal_title：Journal of morphology
pub_type： 杂志文章
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journal_title：Journal of morphology
pub_type： 杂志文章
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journal_title：Journal of morphology
pub_type： 杂志文章
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更新日期：2009-03-01 00:00:00
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journal_title：Journal of morphology
pub_type： 杂志文章
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更新日期：1994-12-01 00:00:00
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pub_type： 杂志文章
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更新日期：2018-09-01 00:00:00
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journal_title：Journal of morphology
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更新日期：2019-05-01 00:00:00
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journal_title：Journal of morphology
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更新日期：2005-06-01 00:00:00
abstract：:The Hula Painted Frog (Latonia nigriventer) is a rare frog species endemic to the Hula Valley, Israel. The species is the sole relict of a clade that was widespread mainly in Europe from the Oligocene until the beginning of the Pleistocene. The osteological characteristics of L. nigriventer are described based on X-ra...
journal_title：Journal of morphology
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更新日期：2016-09-01 00:00:00
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journal_title：Journal of morphology
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更新日期：2016-05-01 00:00:00
abstract：:The antennal circulatory organ of Periplaneta americana and Blaberus craniifer was investigated by light and electron microscopy. This organ consists of two pulsatile ampullae located near the antennal base which are interconnected by a large transverse muscle and associated blood vessels which run into the antennae. ...
journal_title：Journal of morphology
pub_type： 杂志文章
doi：10.1002/jmor.1051850210
更新日期：1985-08-01 00:00:00
abstract：:The differences in angulation and length observed for the fibers of anatomical muscles may reflect two distinct mechanical requirements: arrangement for pinnation, reflecting an increase in physiological cross-section and arrangement for equivalent placement of sarcomeres, possibly associated with coordination. The ob...
journal_title：Journal of morphology
pub_type： 杂志文章
doi：10.1002/jmor.1051920106
更新日期：1987-04-01 00:00:00
