Compatible invasion of a phylogenetically distant host embryo by a hymenopteran parasitoid embryo

Induction and regionalisation of the chick nervous system were investigated by transplanting Hensen's node into the extra-embryonic region (area opaca margin) of a host embryo. Chick/quail chimaeras were used to determine the contributions of host and donor tissue to the supernumerary axis, and three molecular markers, Engrailed, neurofilaments (antibody 3A10) and XlHbox1/Hox3.3 were used to aid the identification of particular regions of the ectopic axis. We find that the age of the node determines the regions of the nervous system that form: young nodes (stages 2–4) induced both anterior and posterior nervous system, while older nodes (stages 5–6) have reduced inducing ability and generate only posterior nervous system. By varying the age of the host embryo, we show that the competence of the epiblast to respond to neural induction declines after stage 4. We conclude that during normal development, the initial steps of neural induction take place before stage 4 and that anteroposterior regionalisation of the nervous system may be a later process, perhaps associated with the differentiating notochord. We also speculate that the mechanisms responsible for induction of head CNS differ from those that generate the spinal cord: the trunk CNS could arise by homeogenetic induction by anterior CNS or by elongation of neural primordia that are induced very early.

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Developmental potential of neural crest-derived cells migrating from segments of developing quail bowel back-grafted into younger chick host embryos

Development ◽

10.1242/dev.109.2.411 ◽

1990 ◽

Vol 109 (2) ◽

pp. 411-423 ◽

Cited By ~ 11

Author(s):

T.P. Rothman ◽

N.M. Le Douarin ◽

J.C. Fontaine-Perus ◽

M.D. Gershon

Keyword(s):

Neural Crest ◽

Neural Tube ◽

Peripheral Nerves ◽

Sympathetic Ganglia ◽

Limb Bud ◽

Pigment Cells ◽

Developmental Potential ◽

Migratory Experience ◽

Host Embryo

The technique of back-transplantation was used to investigate the developmental potential of neural crest-derived cells that have migrated to and colonized the avian bowel. Segments of quail bowel (removed at E4) were grafted between the somites and neural tube of younger (E2) chick host embryos. Grafts were placed at a truncal level, adjacent to somites 14–24. Initial experiments, done in vitro, confirmed that crest-derived cells are capable of migrating out of segments of foregut explanted at E4. The foregut, which at E4 has been colonized by cells derived from the vagal crest, served as the donor tissue. Comparative observations were made following grafts of control tissues, which included hindgut, lung primordia, mesonephros and limb bud. Additional experiments were done with chimeric bowel in which only the crest-derived cells were of quail origin. Targets in the host embryos colonized by crest-derived cells from the foregut grafts included the neural tube, spinal roots and ganglia, peripheral nerves, sympathetic ganglia and the adrenals, but not the gut. Donor cells in these target organs were immunostained by the monoclonal antibody, NC-1, indicating that they were crest-derived and developing along neural or glial lineages. Some of the crest-derived cells (NC-1-immunoreactive) that left the bowel and reached sympathetic ganglia, but not peripheral nerves or dorsal root ganglia, co-expressed tyrosine hydroxylase immunoreactivity, a neural characteristic never expressed by crest-derived cells in the avian gut. None of the cells leaving enteric back-grafts produced pigment. Cells of mesodermal origin were also found to leave donor explants and aggregate in dermis and feather germs near the grafts. These observations indicate that crest-derived cells, having previously migrated to the bowel, retain the ability to migrate to distant sites in a younger embryo. The routes taken by these cells appear to reflect, not their previous migratory experience, but the level of the host embryo into which the graft is placed. Some of the population of crest-derived cells that leave the back-transplanted gut remain capable of expressing phenotypes that they do not express within the bowel in situ, but which are appropriate for the site in the host embryo to which they migrate.

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A developmental pathway controlling outgrowth of the Xenopus tail bud

Development ◽

10.1242/dev.126.8.1611 ◽

1999 ◽

Vol 126 (8) ◽

pp. 1611-1620 ◽

Cited By ~ 3

Author(s):

C.W. Beck ◽

J.M. Slack

Keyword(s):

Normal Development ◽

Posterior Part ◽

Neural Plate ◽

General Mechanism ◽

Developmental Pathway ◽

Tail Bud ◽

Neural Tubes ◽

Tailbud Stage ◽

Tail Tip ◽

Host Embryo

We have developed a new assay to identify factors promoting formation and outgrowth of the tail bud. A piece of animal cap filled with the test mRNAs is grafted into the posterior region of the neural plate of a host embryo. With this assay we show that expression of a constitutively active Notch (Notch ICD) in the posterior neural plate is sufficient to produce an ectopic tail consisting of neural tube and fin. The ectopic tails express the evenskipped homologue Xhox3, a marker for the distal tail tip. Xhox3 will also induce formation of an ectopic tail in our assay. We show that an antimorphic version of Xhox3, Xhox3VP16, will prevent tail formation by Notch ICD, showing that Xhox3 is downstream of Notch signalling. An inducible version of this reagent, Xhox3VP16GR, specifically blocks tail formation when induced in tailbud stage embryos, comfirming the importance of Xhox3 for tail bud outgrowth in normal development. Grafts containing Notch ICD will only form tails if placed in the posterior part of the neural plate. However, if Xwnt3a is also present in the grafts they can form tails at any anteroposterior level. Since Xwnt3a expression is localised appropriately in the posterior at the time of tail bud formation it is likely to be responsible for restricting tail forming competence to the posterior neural plate in our assay. Combined expression of Xwnt3a and active Notch in animal cap explants is sufficient to induce Xhox3, provoke elongation and form neural tubes. Conservation of gene expression in the tail bud of other vertebrates suggests that this pathway may describe a general mechanism controlling tail outgrowth and secondary neurulation.

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Immunological Attack by Adult Cells in the Developing Chick Embryo: Influence of the Vascularity of the Host Spleen and of Homograft Rejection by the Embryo on Splenomegaly

Development ◽

10.1242/dev.11.1.119 ◽

1963 ◽

Vol 11 (1) ◽

pp. 119-134

Author(s):

J. B. Solomon ◽

D. F. Tucker

Keyword(s):

Chick Embryo ◽

Donor Cells ◽

Host Embryo ◽

Immunological Attack ◽

Adult Cells

The immunological attack by adult cells introduced into the embryo is first manifest by splenomegaly. The extent of this splenomegaly depends upon many factors. There must be antigenic differences between the donor and host in that the host must possess antigens absent in the donor (Cock & Simonsen, 1958; Mun, Kosin & Sato, 1959; Burnet & Boyer, 1961; Jaffe & Payne, 1961). The degree of splenomegaly also depends upon the immunological maturity of the donor cells (Ebert, 1951; Simonsen, 1957; Solomon, 1960, 1961a), the number of donor cells injected into the embryo (Isacson, 1959; Terasaki, 1959a; Solomon, 1962) and, in some cases, upon the sex of the host (Solomon, 1962). In this paper two further factors are shown to affect splenomegaly—the age of the host embryo and the method of administration of the donor cells. Danchakoff (1916) first showed that the histology of the spleen during splenomegaly varied with the age of the host without being aware of the nature of the transplantation reactions involved.

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The road to generating transplantable organs: from blastocyst complementation to interspecies chimeras

Development ◽

10.1242/dev.195792 ◽

2021 ◽

Vol 148 (12) ◽

Author(s):

Canbin Zheng ◽

Emily B. Ballard ◽

Jun Wu

Keyword(s):

Science Fiction ◽

Pluripotent Stem Cells ◽

Current Status ◽

Divergent Evolution ◽

Closely Related Species ◽

The Road ◽

Human Organs ◽

Blastocyst Complementation ◽

Donor Cells ◽

Host Embryo

ABSTRACT Growing human organs in animals sounds like something from the realm of science fiction, but it may one day become a reality through a technique known as interspecies blastocyst complementation. This technique, which was originally developed to study gene function in development, involves injecting donor pluripotent stem cells into an organogenesis-disabled host embryo, allowing the donor cells to compensate for missing organs or tissues. Although interspecies blastocyst complementation has been achieved between closely related species, such as mice and rats, the situation becomes much more difficult for species that are far apart on the evolutionary tree. This is presumably because of layers of xenogeneic barriers that are a result of divergent evolution. In this Review, we discuss the current status of blastocyst complementation approaches and, in light of recent progress, elaborate on the keys to success for interspecies blastocyst complementation and organ generation.

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Fate of genetically marked mitochondrial DNA from spermatocytes microinjected into mouse zygotes

Zygote ◽

10.1017/s0967199499000519 ◽

1999 ◽

Vol 7 (2) ◽

pp. 151-156 ◽

Cited By ~ 11

Author(s):

James M. Cummins ◽

Hidefumi Kishikawa ◽

Denise Mehmet ◽

Ryuzo Yanagimachi

Keyword(s):

Mitochondrial Dna ◽

Germ Cells ◽

Restriction Site ◽

Mutual Recognition ◽

Nuclear Genome ◽

Pcr Amplification ◽

Cell Stage ◽

Mt Dna ◽

Mouse Zygotes ◽

Host Embryo

Cytoplasts from single spermatocytes of NZB/BinJ mice were separated from the nuclei and individually microinjected into B6D2F1 (C57BL/6 × DNBA/2J) hybrid embryos at the pronuclear stage (20 h after hCG injection). Of 363 zygotes injected, 311 (86%) survived and developed. From these experiments, we transferred 222 embryos into 20 pseudopregnant recipients. Eighteen (90%) became pregnant and 82 pups were born (37% of transfers). Mitochondrial DNA (mt DNA) from the NZB/BinJ strain lacks a RsaI restriction site and can thus be distinguished from the host embryo following PCR amplification. We were unable to detect the transferred mtDNA in blastocysts on day 4–5 after injection. Nor could we detect NZB/BinJ mtDNA in placentae, nor in tissues from mice born to host mothers following the transfer of blastocysts that developed from injected zygotes. Rejection of paternal mitochondria by the embryo normally occurs at the 4- to 8-cell stage in mice and is apparently dependent on mutual recognition between the mitochondria and the nuclear genome. We conclude that this mechanism has probably already developed by the time the germ cells have become committed to meiosis.

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Analyse de la morphogenèse du pied des Oiseaux à l'aide de mélanges cellulaires interspécifiques

Development ◽

10.1242/dev.29.1.175 ◽

1973 ◽

Vol 29 (1) ◽

pp. 175-196

Author(s):

Par Marie-Paule Pautou

Keyword(s):

Cell Suspension ◽

The Other ◽

Composite Type ◽

A Cell ◽

Species Specific ◽

Host Embryo

Morphogenesis of the feet of birds, studied in limbs developed from reaggregated heterospecific mesoderm Experiments were undertaken to determine whether species-specific characters of chick and duck mesodermal leg-bud cells are retained after dissociation and reaggregation in homoand heterospecific mixtures. Prospective zeugopod and autopod mesoderm from chick and/or duck leg buds were isolated, dissociated into a cell suspension and pelleted by centrifugation. The reaggregated mesoderm was packed into a leg-bud ectodermal jacket; the recombined leg bud was then grafted on the wing stump of a host embryo. Recombinants whose mesoderm was a homospecific reaggregate developed into typical chick or duck leg parts according to the specific origin of the mesodermal component; the feet of nearly all these legs lacked antero-posterior polarity. Recombinants containing heterospecific reaggregates were also capable of forming reasonably organized leg structures. The foot was not, as a rule, of the specific type expected of the majority component. In a mixture of 75% chick mesoderm cells and 25% duck mesoderm cells, the feet which developed were either of chick type or of composite chick/duck type, where typical chick areas were next to typical or aberrant (steganoid) duck areas. When the ratio was reversed (25% chick, 75% duck), the majority of the feet were again of chick type or of composite chick/duck type, the typical duck phenotype being exceptional. Even in a mixture of 10% chick cells and 90% duck cells, duck-type feet were not obtained. They were all of composite type: half of their interdigital zones were of chick type, the other half were occupied, in most cases, by underdeveloped, indented webbing or by one or several discrete flaps, and, in a few cases, by normal webbing. The vast majority of the feet developed from heterospecific mesoderm were characterized by the profusion of the toes, which were not polarized along the a–p axis.

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Mesoderm-inducing factors and Spemann's organiser phenomenon in amphibian development

Development ◽

10.1242/dev.107.2.229 ◽

1989 ◽

Vol 107 (2) ◽

pp. 229-241 ◽

Cited By ~ 1

Author(s):

J. Cooke

Keyword(s):

Growth Factor ◽

Pattern Formation ◽

Marginal Zone ◽

Natural Control ◽

Graft Size ◽

Two Factors ◽

Inducing Factors ◽

Mesoderm Inducing Factors ◽

Host Embryo ◽

Factor Concentration

Certain proteins from ‘growth factor’ families can initiate mesodermal development in animal cap cells of the amphibian blastula. Cells that are in early stages of their response to one such factor, XTC-MIF (Smith et al. 1988), initiate the formation of a new axial body plan when grafted to the ventral marginal zone of a similarly aged host embryo (Cooke et al. 1987). This replicates the natural control of this phase of development by the dorsal blastoporal lip when similarly grafted; the classical ‘organiser’ phenomenon. I have explored systematically the effect, upon the outcome of this pattern formation using defined inducing factors, of varying graft size, XTC-MIF concentration to which graft cells were exposed, length of exposure before grafting, and host age. The ‘mesodermal organiser’ status, evoked by the factor, appears to be stable, and the variables most influencing the degree of completeness and orderliness of second patterns are graft size and factor concentration. Inappropriately large grafts are not effective. A Xenopus basic fibroblast growth factor homologue, present in the embryo and known to be a strong inducer but of mesoderm with a different character from that induced by XTC-MIF, produced no episode of pattern formation at all when tested in the procedure described in this paper. Organiser status of grafts that have been exposed to mixtures of the two factors is set entirely by the supplied XTC-MIF concentration. Lineage labelling of these grafts, and of classical dorsal lip grafts, reveals closely similar though not identical patterns of contribution to the new structure within the host. Implications of the results for the normal mechanism of body pattern formation are discussed.

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90 GERM-LINE TRANSMISSION OF DONOR MITOCHONDRIAL DNA IN NUCLEAR TRANSFER-DERIVED COWS

Reproduction Fertility and Development ◽

10.1071/rdv19n1ab90 ◽

2007 ◽

Vol 19 (1) ◽

pp. 162

Author(s):

K. Takeda ◽

K. Kaneyama ◽

M. Tasai ◽

S. Akagi ◽

M. Yonai ◽

...

Keyword(s):

Mitochondrial Dna ◽

Nuclear Transfer ◽

Germ Line ◽

Donor Cell ◽

Cumulus Cells ◽

Single Strand Conformation Polymorphism ◽

Loop Region ◽

D Loop ◽

Germ Line Transmission ◽

Host Embryo

In embryos derived by nuclear transfer (NT), fusion, or injection of donor cells with recipient oocytes caused mitochondrial heteroplasmy. Previous studies have reported varying patterns of mitochondrial DNA (mtDNA) transmission in cloned calves. Distribution of donor mtDNA found in offspring of NT-derived founders may also vary from donor–host embryo heteroplasmy to host embryo homoplasmy. Here we examined the transmission of mtDNA from NT cows to their progeny. NT cows were originally produced by fusion of enucleated oocytes with Jersey (J) or Holstein (H1) oviduct epithelial cells, or Holstein (H2) or Japanese Black (B) cumulus cells, as previously reported (Goto et al. 1999 Anim. Sci. J. 70, 243–245; Yonai et al. 2005 J. Dairy Sci. 88, 4097–4110; Akagi et al. 2003 Mol. Reprod. Dev. 66, 264–272). Transmission of donor cell mtDNA was analyzed by PCR-mediated single-strand conformation polymorphism (PCR-SSCP) analysis of the mitochondrial D-loop region. Eleven NT founder cows were analyzed, 4 (2 = J-NT, and 2 = H1-NT) of them were heteroplasmic whereas 7 (1 = J-NT, 1 = H1-NT, 2 = H2-NT, and 3 = B-NT) were homoplasmic for the host embryo mitochondria. The proportions of donor mtDNA detected in one J-NT cow was 7.7%, and those of other cow lineages were <2%. Heteroplasmic NT cows delivered a total of 9 progeny. Four of the 9 progeny exhibited heteroplasmy with high percentages of donor cell mtDNA populations (52%, 37%, 17%, and 43%). The other 5 progeny were obtained from heteroplasmic NT cows, and all samples of the 10 progeny obtained from the homoplasmic NT cows did not harbor detectable donor cell mtDNA. A genetic bottleneck in the female germ-line will generally favor the transmission of a single mitochondrial population, leading to a return to homoplasmy. Thus, some of progeny maintained heteroplasmy with a higher ratio than that of their NT mothers, which may also reflect a segregation distortion caused by the proposed mitochondrial bottleneck. These results demonstrated that donor mtDNA in NT cows could be transmitted to progeny with varying efficiencies, in a lineage-specific fashion.

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