Structure of the brachiopod lophophore

Kuzmina, T. V.; Малахов, В. В.

doi:10.1134/s0031030107050073

Cited by 24 publications

(34 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This is particularly important during feeding, when the lophophoral tentacles extend well beyond the edge of the widely gaping shell (Atkins, 1960; Alvarez et al, 2008). A behavior also observed in other brachiopods with fused lophophores such as thecideoids (Kuzmina and Malakhov, 2007). Thecideoids, who's fossil ancestors also successfully invaded the scleractinian reefs in the Mesozoic (Baker, 2006), support their lophophore against the external water currents with calcareous structures, which can restrict the space in the mantle cavity extremely as in Pajaudina atlantica Logan, 1988 (Alvarez et al, 2008).…”

Section: Discussionsupporting

confidence: 63%

Linking micromorphism, brooding, and hermaphroditism in brachiopods: Insights from Caribbean Argyrotheca (Brachiopoda)

Kaulfuss

Seidel

Lüter

2013

Journal of Morphology

View full text Add to dashboard Cite

In extant brachiopods, parental brooding of the larvae occurs exclusively within Rhynchonelliformea. Methods of larval protection range from simple retention of the larvae within the mantle cavity, to sophisticated brood care within highly specialized brood pouches found in Argyrotheca and Joania (Terebratulida, Megathyridoidea), Gwynia (Terebratulida, Gwynioidea), and all Thecideoidea (Thecideida). Previous studies on the reproductive biology of Argyrotheca yielded contrasting results on the epithelial origin of the brood pouches in this genus. Here, representatives of different species of Argyrotheca from the Belize Barrier Reef were examined using histological section series. Brood pouches of four species, A. cf. schrammi and Argyrotheca sp. 1-3, are of the same basic structure, formed by invaginations of the anterior body wall and connected to the visceral cavity via the metanephridia. The same four species are simultaneously hermaphroditic, suggesting that fertilization is achieved, at least partly, through selfing. One species, Argyrotheca rubrocostata, differs significantly from all others as it has no brood pouch and gonochoric gonads. Thus, the presence of brood pouches and simultaneous hermaphroditism are concluded to be correlated within Megathyridoidea and proposed to be homologous traits of Joania and several but not all species of Argyrotheca, questioning the monophyletic status of both genera. In contrast to the brood pouches of Thecideoidea, lophophoral epithelium is not involved in the formation of the pouches of Argyrotheca and Joania. Therefore, megathyridoid and thecideoid brood pouches are not homologous but evolved independently within rhynchonelliform brachiopods. All brachiopods with brood pouches share a micromorphic form and a short life span, limiting the space and time available for gamete and larval development. We suggest that the brood pouches and the hermaphroditic gonads of Argyrotheca spp. and Joania compensate these limitations by minimizing the loss of gametes and larvae, and by maximizing the chances of successful fertilization.

show abstract

Section: Discussionsupporting

confidence: 63%

Linking micromorphism, brooding, and hermaphroditism in brachiopods: Insights from Caribbean Argyrotheca (Brachiopoda)

Kaulfuss

Seidel

Lüter

2013

Journal of Morphology

View full text Add to dashboard Cite

show abstract

“…2C, F, I). The remnant of the larval anterior lobe, from which the prospective lophophore will develop [65, 74], is situated inside the mantle cavity ( lr , Figs. 2B; 3B, B’, C, C’).…”

Section: Resultsmentioning

confidence: 99%

Hox gene expression in postmetamorphic juveniles of the brachiopod Terebratalia transversa

Gąsiorowski

Hejnol

2018

Preprint

View full text Add to dashboard Cite

Background: Hox genes encode a family of homeodomain containing transcription factors that are clustered together on chromosomes of many Bilateria. Some bilaterian lineages express these genes during embryogenesis in spatial and/or temporal order according to their arrangement in the cluster, a phenomenon referred to as collinearity. Expression of Hox genes is well studied during embryonic and larval development of numerous species; however, relatively few studies focus on the comparison of pre- and postmetamorphic expression of Hox genes in animals with biphasic life cycle. Recently, the expression of Hox genes was described for embryos and larvae of Terebratalia transversa, a rhynchonelliformean brachiopod, which possesses distinct metamorphosis from planktonic larvae to sessile juvenile. During premetamorphic development, T. transversa does not exhibit spatial collinearity and several of its Hox genes are recruited for the morphogenesis of novel structures. In our study we determined expression of Hox genes in post-metamorphic juveniles of T. transversa in order to examine metamorphosis-related changes of expression patterns and to test if Hox genes are expressed in the spatially collinear way in the postmetamorphic juveniles. Results: Hox genes are expressed in a spatially non-collinear manner in juveniles, generally showing similar patterns as ones observed in competent larvae: genes labial and Post1 are expressed in chaetae-related structures, sex comb reduced in the shell forming epithelium, whereas Lox5 and Lox4 in dorso-posterior epidermis. After metamorphosis expression of genes proboscipedia, Hox3, Deformed and Antennapedia becomes restricted to, respectively, shell musculature, prospective hinge rudiments, and pedicle musculature and epidermis. Conclusions: All developmental stages of T. transversa, including postmetamorphic juveniles, exhibit a spatial non-collinear Hox genes expression with only minor changes observed between pre- and postmetamorphic stages. Our results are concordant with morphological observation that metamorphosis in rhynchonelliformean brachiopods, despite being rapid, is rather gradual. The most drastic changes in Hox genes expression patterns observed during metamorphosis could be explained by the inversion of the mantle lobe, which relocates some of the more posterior larval structures into the anterior edge of the juveniles. Cooption of Hox genes for the morphogenesis of novel structures is even more pronounced in post-metamorphic brachiopods when compared to larvae.

show abstract

“…Similarly, in rhynchonelliformean and craniiformean brachiopods none of the Hox genes are expressed in the larval anterior lobe (16,40), which contributes to the lophophore after metamorphosis (112). A lack of Hox expression in the adult lophophore tissue (as opposed to the remaining body regions) was shown for the linguliformean Lingula anatina, based on the tissue specific transcriptomics (89).…”

Section: Hox Gene Expression and The Nature Of Actinotrocha Larvaementioning

confidence: 95%

“…According to the first hypothesis, the actinotrocha larva might represent an evolutionary novelty in the life cycle of phoronids, which was intercalated in the phoronid lineage and that is why it is not patterned by an ancestral Hox gene system. Such idea is supported by the fact, that the actinotrocha does not bear obvious homology to any other spiralian larvae (80,111,112). Moreover, the actinotrocha is lacking in Ph.…”

Section: Hox Gene Expression and The Nature Of Actinotrocha Larvaementioning

confidence: 99%

See 1 more Smart Citation

Hox gene expression during the development of the phoronidPhoronopsis harmeri

Gąsiorowski

Hejnol

2019

Preprint

View full text Add to dashboard Cite

Background: Phoronida is a small group of marine worm-like suspension feeders, which together with brachiopods and bryozoans form the clade Lophophorata. Although their development is well studied on the morphological level, data regarding gene expression during this process are scarce and restricted to the analysis of relatively few transcription factors. Here we present a description of the expression patterns of Hox genes during the embryonic and larval development of the phoronid Phoronopsis harmeri. Results:We identified sequences of 8 Hox genes in the transcriptome of P. harmeri and determined their expression pattern during embryonic and larval development using whole mount in situ hybridization. We found that none of the Hox genes is expressed during embryonic development. Instead their expression is initiated in the later developmental stages, when the larval body is already formed. The Hox genes are expressed in the metasomal sac, posterior mesoderm and junction between midgut and hindgut -structures that represent rudiments of the adult worm, which emerges through the process of drastic

show abstract

Structure of the brachiopod lophophore

Cited by 24 publications

References 25 publications

Linking micromorphism, brooding, and hermaphroditism in brachiopods: Insights from Caribbean Argyrotheca (Brachiopoda)

Linking micromorphism, brooding, and hermaphroditism in brachiopods: Insights from Caribbean Argyrotheca (Brachiopoda)

Hox gene expression in postmetamorphic juveniles of the brachiopod Terebratalia transversa

Hox gene expression during the development of the phoronidPhoronopsis harmeri

Contact Info

Product

Resources

About