What does abra evolve into a relationship

Abra (Pokémon) - Bulbapedia, the community-driven Pokémon encyclopedia

what does abra evolve into a relationship

Pokédex entry for #63 Abra containing stats, moves learned, evolution chain, location and more! Abra is a Psychic type Pokémon introduced in Generation 1 . Abra (Japanese: ケーシィ Casey) is a Psychic-type Pokémon introduced in Generation I. It evolves into Kadabra starting at level 16, which evolves into Alakazam. Machoke isn't all that hard to find, but it can only evolve into Machamp Abra is one of the most notoriously difficult Pokémon to capture in the.

We study the mechanisms of visual degeneration in the Mexican Tetra, Astyanax mexicanus, a single species consisting of a surface-dwelling form surface fish Fig. The Mexican tetra is easy to raise in the laboratory and exhibits many of the attributes that have made zebrafish a popular model system in developmental biology.

These features include external fertilization, frequent and abundant spawning, transparent embryos, a 4—6 month generation time, and the opportunity for molecular, developmental, and genetic analysis.

The surface and cave forms of A. Because of these attributes Astyanax cavefish represent one of the few cave animals in which laboratory experiments can be conducted on the mechanisms of eye degeneration and these mechanisms can be compared in the same species from different caves.

Here we review current progress on the evolution and development of Astyanax cavefish and discuss how these studies have contributed to understanding the evolutionary basis of eye degeneration. Did all cavefish populations originate from a common ancestor and lose their eyes only once or did they evolve many times and lose their eyes independently? Different approaches have been used to determine the evolutionary relationships of cavefish, including allozyme analysis, biogeography, and phylogenetic reconstruction using molecular sequences.

We will briefly consider the results obtained from the first two approaches and then describe the phylogenetic studies in more detail. Figure 2 shows a map of the Sierra de El Abra region in northeastern Mexico illustrating the locations of known caves harboring Astyanax cavefish populations. An outlying cavefish population has also been discovered in the state of Guererro in south central Mexico Espinasa et al. In an electrophoretic study showing minimal divergence in 17 allozyme loci, Avise and Selander concluded that the Sierra de El Abra cavefish had a common origin.

In contrast, Mitchell et al. The possibility of multiple cavefish origins is strongly supported by the recently discovered Guerrero cavefish from a cave located several hundred miles southwest of the main cavefish region Espinasa et al.

The limited number of RAPD markers scored in this study, however, left some uncertainty about the true relationships among the Sierra de El Abra cavefish.


Thus far, it has proved difficult to obtain sufficiently variable sequence information from nuclear genes to construct robust phylogenetic trees, presumably due to the recent divergence of surface fish and cavefish. Thus, Dowling et al. Some taxonomists recognize two separate Astyanax species in Mexico: Others believe that all Mexican and Central American Astyanax are a single species, Astyanax fasciatus see Wilkens, Here, we defer to the first classification, designating the northern Mexican form as A.

Our justification is that these taxa are strongly supported by the mtDNA phylogeny Fig. The mtDNA phylogeny infers at least two separate origins of cavefish, one before the divergence of the present day A. Accordingly, two distinct mtDNA lineages are recognized: The A lineage exhibits one of more than 20 different Type A ND-2 haplotypes, which vary from each other in only a few nucleotide positions and are mostly represented in surface fish.

The B lineage exhibits one or two of only a few Type B ND-2 haplotypes, which differ in 7 or more nucleotide sites from the Type A haplotypes and are present in cavefish but not in any nearby surface fish populations.

Abra, Kadabra, and Alakazam - Wikipedia

Although the mtDNA tree has strong bootstrap support, our interpretation of these data must be treated with caution. First, the tree is based on only a single gene. However, a recent phylogenetic analysis has confirmed the topology of this tree using a different mitochondrial gene, cytochrome b Strecker et al. Second, mtDNA trees could be influenced by hybridization, which is known to have occurred between some of the cavefish populations and nearby surface fish Mitchell et al.

Third, a recent phylogeny using microsatellite loci is more consistent with a common origin of the Sierra de El Abra cavefish Strecker et al. It is clear from the mtDNA data, however, that A and B lineage cavefish are genetically isolated populations.

Below we will compare the developmental mechanisms of eye degeneration in some of these cavefish. In every cavefish population we have studied, the eye primordium appears to be smaller than its surface fish counterpart.

However, the cavefish eye seems to develop normally up to about the hatching stage, forming a lens and optic cup. Subsequently, development gradually arrests, the retina becomes disordered, and the degenerating eye disappears into the orbit Cahn, ; Langecker et al.

The cavefish lens does not differentiate arrays of aligned crystallin fibers and the retina, although at first layered normally, eventually shows disorganization and complete or partial loss of photoreceptor cells. In many developing systems, an alternative to cell differentiation is apoptosis: Therefore, we first investigated whether apoptosis occurred during cavefish eye development.

If cell death is restricted to a single eye tissue, or begins in one tissue and later spreads to others, then the tissue that dies first is a strong candidate to initiate the degeneration process. Surface fish embryos showed little or no programmed cell death in the developing eye Fig. Cavefish showed the same apoptotic event in a small number of isthmus cells as the lens vesicle pinched off from the surface ectoderm. About a day after the cavefish lens vesicle was formed, however, an additional and more extensive episode of apoptosis was detected in its central core Fig.

No apoptosis was detected at this time in the surface fish lens Fig. A few days later, the retina began to undergo apoptosis. Retinal cell death is restricted to the outer nuclear layer and the region adjacent to the ciliary marginal zone CMZ A.

Kadabra (Pokémon)

Does the embryonic lens also die in other cavefish populations? The results suggest that lens apoptosis may be responsible for triggering eye degeneration in both A and B lineage cavefish. The cessation of retinal growth in cavefish could be caused by the failure of the dying lens to produce a growth-promoting factor or it could be due to an independent event in the retina.

what does abra evolve into a relationship

A reasonable candidate for an independent retinal event would be interference with cell proliferation. Surface fish have an active CMZ. Presumably, new cells are removed from the retina soon after they are formed by the apoptotic events that begin a few days after the initiation of lens cell death.

We next asked whether the surprisingly wasteful process in which retinal cells appear to cycle quickly between birth and death also occurs in other cavefish populations? Thus, we conclude that arrest of cell proliferation is not the major cause of eye degeneration in A and B lineage cavefish populations. The results described above focus our attention back to the lens. Does the lens organize the whole eye and could its removal by apoptosis result in the arrest of eye formation?

The central role of the lens in eye formation has recently been appreciated Beebe and Coats, ; Thut et al. We developed a lens transplantation assay to determine the role of the lens in surface fish eye development and in cavefish eye degeneration Yamamoto and Jeffery, The embryonic lens was removed from a donor embryo shortly after it pinched off from the surface ectoderm, about a day before the first detection of large-scale apoptosis in the cavefish lens, and it was transplanted into the optic cup of a host embryo.

Lens transplantation was done unilaterally, with the unoperated eye of the host serving as a control. These experiments also addressed the autonomy of programmed cell death in the cavefish lens: When a cavefish lens was transplanted into a surface fish optic cup it died on schedule, just as if it had not been removed from the donor embryo.

Likewise, when a surface fish lens was transplanted into a cavefish optic cup it continued to grow and differentiated as it would have in the surface fish host. The autonomy of surface fish lens development in the cavefish host is the key part of the transplantation experiment. Eventually, the cornea and iris appeared, which are normally missing in cavefish, and the retina enlarged and became more organized.

When the donor lens was labeled with GFP no labeled cells appeared in the restored tissues of the host Yamamoto and Jeffery, Thus, the rescued eye tissues arise from the host and not the donor. The cornea and iris are derived in part from optic neural crest cells, indicating that cavefish neural crest cells are present and located in the proper positions to be induced by the lens.

In contrast to the eye with a transplanted lens, the unoperated eye of the cavefish host degenerated and disappeared into the orbit according to its usual schedule Fig.

what does abra evolve into a relationship

Likewise, after obtaining a cavefish lens, development of the surface fish eye was retarded, the cornea and iris did not differentiate, and the size and organization of the retina was reduced.

The degenerate surface fish eye eventually disappeared into the orbit Fig. In contrast, the unoperated eye developed normally Fig. Several conclusions can be made from the lens transplantation experiments. First, the lens is an organizer of optic development, mediating differentiation of the cornea and iris and survival and growth of the retina and cornea. Whether the lens sends an instructive or a permissive signal to these tissues is currently under investigation. Second, the cavefish lens has lost the ability to organize the eye, presumably as a result of apoptosis.

Third, despite the loss of its own lens, the cavefish eye and accessory tissues have retained the ability to respond to signals generated by a normal surface fish lens. We next asked whether the lens is central to eye degeneration in other cavefish populations. The lens transplantation experiments were repeated in Los Sabinos cavefish Fig.

The results were the same: In both cases, evolutionary changes have targeted the lens. This resource prompted us to take a candidate gene approach to characterize the genes involved in cavefish eye degeneration. The approach involves obtaining the sequences of known eye genes by Reverse Transcription PCR with degenerate primers and comparing their expression patterns in surface fish and cavefish embryos by in situ hybridization. Our candidate gene survey includes genes encoding transcription factors that function near the top of eye gene hierarchies, as well as structural genes encoding proteins that function at the bottom of the gene cascades.

Most of the surveyed genes did not show any changes in expression in surface fish and cavefish embryos. The gamma crystallin protein is also synthesized in the cavefish lens A. Kadabra and Alakazam have relatively large mustaches, which are shorter in female species. Kadabra has a red star -shaped symbol on its forehead, and three red wavy lines on its fauld-like torso. After evolving into Alakazam, the creatures no longer have the Zener markings and tails, [6] while their heads become much larger, resulting in extremely powerful mental powers.

Alakazam undergoes slight changes upon Mega Evolving into Mega Alakazam, as its overall color scheme becomes slightly paler, it gains a white beard alongside its now white mustache, a considerably thinner torso, and a red gem-like organ on its forehead.

When encountered in the wild, Abra will always use Teleport to attempt to escape the battle on the first turn. Abra evolves into Kadabra after gaining enough experience in battle, and Kadabra evolves into Alakazam after being traded to another trainer. Abra and Kadabra later appear in every subsequent sequel. Ultimateusing Teleport to warp itself and fighters off the stage, potentially KO'ing them. After battling, Sabrina's Abra evolves into Kadabra, causing Ash to forfeit the match due to Kadabra's new and more powerful psychic abilities.

Because of Kadabra and Sabrina's laughter, they are unable to fight, and hand over the gym badge. Blue captures all of them with his Scizor. Calling Abra "cute", they described Kadabra as having "a bit of that personality", and Alakazam as being a "distinctly grim, foreboding character".