Sexual reproduction

Lab-Grown Penis In Final Steps Of Testing: Why A Sense Of Normalcy Is More Than Just An Erection

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Becoming a victim of dismemberment due to a car accident, time spent on the battlefield, or being born with a genital abnormality, can lead to grievous psychological complications throughout a man’s life. Researchers at the Wake Forest Institute for Regenerative Medicine in North Carolina recognized the mental and emotional hurdles a man without a penis would lead with the possibility of gender identity loss and a self-conscious romantic life. After nearly 25 years of laboratory grown penis experiments, researchers have reached the safety stage and will soon be testing on human men.

Penises Provide Gender Identity More Than An Erection

“The rabbit studies were very encouraging,” Dr. Anthony Atala, a pediatric urological surgeon and the director of the Institute, who oversaw the team’s successful engineering of penises for rabbits in 2002 and 2008, told The Guardian. “But to get approval for humans we need all the safety and quality assurance data, we need to show that the materials aren’t toxic, and we have to spell out the manufacturing process, step by step.”

Atala began his work in 1992, specializing in treating children born with genital abnormalities. After finding success in the earlier stages of Atala’s penis project in 2002, he said it was not only impressive that they were able to reconstruct a penis, but a real medical milestone in tissue and organ engineering because the penis is one of the most complex organs they’ve attempted to engineer. His team already successfully created fully functional bladders in 1999, but the penis has several functions to complicate the process, unlike the bladder.

The penis is still unable to achieve an erection, which limits them from penetration and ultimately our most fundamental instinct: reproduction. But the function of a penis goes beyond the physical aspect and enters an important realm in a male’s mental perspective. Without a penis, a man can experience castration anxiety, which Sigmund Freud discussed in one of his earliest psychoanalytic theories based on the overwhelming fear of damage or loss of one’s penis. It’s typically caused by already existing penile damage that haunts a man throughout his life, even if it hasn’t limited his sexual reproduction.

With the alarming rate of mutilation to the U.S. troops in Afghanistan, it is of utmost importance a man reinstates his identity by having a penis despite its inability to achieve an erection. The number of U.S. soldiers who experienced severe genital wounds tripled in 2011, and the loss of one limb doubled from 2008 to 2010 because of an increase in improvised explosive devices (IED) used on the battlefield, according to the Army Times. One Marine, and undoubtedly many more, reported if he lost his manhood he wouldn’t want to live through it. This isn’t about just being able to have sex; this is ensuring men have the ability to identify their gender and to reinstate strength and masculinity after such a devastating loss.

“Our target is to get the organs into patients with injuries or congenital abnormalities,” said Atala, whose research is currently funded by the U.S. Armed Forces Institute of Regenerative Medicine with a long-term goal of providing penis regrowth procedures for soldiers sustaining battlefield injuries. However, his original passion stemmed from preventing newborn baby boys from being given a sex-change at birth due to being born with ambiguous genitalia. “Imagine being genetically male but living as a woman. It’s a firmly devastating problem that we hope to help with.”

Limitations Of Laboratory Penises

Currently, the method limits Atala’s team from providing female-to-male sex reassignment surgery because it requires a patient’s own penis-specific cells. These newly grown penises have only gone through testing with rabbits and are currently undergoing the safety, function, and durability testing to prepare them for human testing in the next five years. The penises are used with a donor penis and sanitized to expunge any donor cells and then the male patient’s own cells are grown in culture for four to six weeks and injected into the shaft — muscle and blood vessel cells and all. The trick is using a male’s own cells to dramatically decrease the risk of immunological rejection, which occurs when the body recognizes it as a foreign and dangerous invader.

“My concern is that they might struggle to recreate a natural erection,” Atala said. “Erectile function is a coordinated neurophysiological process starting in the brain, so I wonder if they can reproduce that function or whether this is just an aesthetic improvement. That will be their challenge.”

When first tested with genetically engineered penises in 2002, once the 18 rabbits recovered from their surgery, they attempted to have sex within 30 seconds of being placed in a cage with a female. Atala reported they were able to penetrate and produce sperm with their new generated penises, but at about the stamina and efficacy of a 60-year-old penis, versus their goal of a 30-year-old. Now with the advent of a nearly complete lab-generated penis, Atala and his team hope to achieve erections for sexual intercourse. What is the point of having a penis if you can’t fulfill the most fundamental and innate function of reproduction — arguably the reason for our existence?

“If we can engineer and replace this tissue, these men can have erections again,” said Dr. James Yoo, a collaborator of Atala’s at Wake Forest Institute, who is working on bioengineering and replacing parts of the penis to help treat erectile dysfunction. “As a scientist and clinician, it’s this possibility of pushing forward current treatment practice that really keeps you awake at night.”

Lab-Grown Penis In Final Steps Of Testing: Why A Sense Of Normalcy Is More Than Just An Erection

Posted by

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Becoming a victim of dismemberment due to a car accident, time spent on the battlefield, or being born with a genital abnormality, can lead to grievous psychological complications throughout a man’s life. Researchers at the Wake Forest Institute for Regenerative Medicine in North Carolina recognized the mental and emotional hurdles a man without a penis would lead with the possibility of gender identity loss and a self-conscious romantic life. After nearly 25 years of laboratory grown penis experiments, researchers have reached the safety stage and will soon be testing on human men.

“The rabbit studies were very encouraging,” Dr. Anthony Atala, a pediatric urological surgeon and the director of the Institute, who oversaw the team’s successful engineering of penises for rabbits in 2002 and 2008, told The Guardian. “But to get approval for humans we need all the safety and quality assurance data, we need to show that the materials aren’t toxic, and we have to spell out the manufacturing process, step by step.”

Atala began his work in 1992, specializing in treating children born with genital abnormalities. After finding success in the earlier stages of Atala’s penis project in 2002, he said it was not only impressive that they were able to reconstruct a penis, but a real medical milestone in tissue and organ engineering because the penis is one of the most complex organs they’ve attempted to engineer. His team already successfully created fully functional bladders in 1999, but the penis has several functions to complicate the process, unlike the bladder.

The penis is still unable to achieve an erection, which limits them from penetration and ultimately our most fundamental instinct: reproduction. But the function of a penis goes beyond the physical aspect and enters an important realm in a male’s mental perspective. Without a penis, a man can experience castration anxiety, which Sigmund Freud discussed in one of his earliest psychoanalytic theories based on the overwhelming fear of damage or loss of one’s penis. It’s typically caused by already existing penile damage that haunts a man throughout his life, even if it hasn’t limited his sexual reproduction.

With the alarming rate of mutilation to the U.S. troops in Afghanistan, it is of utmost importance a man reinstates his identity by having a penis despite its inability to achieve an erection. The number of U.S. soldiers who experienced severe genital wounds tripled in 2011, and the loss of one limb doubled from 2008 to 2010 because of an increase in improvised explosive devices (IED) used on the battlefield, according to the Army Times. One Marine, and undoubtedly many more, reported if he lost his manhood he wouldn’t want to live through it. This isn’t about just being able to have sex; this is ensuring men have the ability to identify their gender and to reinstate strength and masculinity after such a devastating loss.

“Our target is to get the organs into patients with injuries or congenital abnormalities,” said Atala, whose research is currently funded by the U.S. Armed Forces Institute of Regenerative Medicine with a long-term goal of providing penis regrowth procedures for soldiers sustaining battlefield injuries. However, his original passion stemmed from preventing newborn baby boys from being given a sex-change at birth due to being born with ambiguous genitalia. “Imagine being genetically male but living as a woman. It’s a firmly devastating problem that we hope to help with.”

Limitations Of Laboratory Penises

Currently, the method limits Atala’s team from providing female-to-male sex reassignment surgery because it requires a patient’s own penis-specific cells. These newly grown penises have only gone through testing with rabbits and are currently undergoing the safety, function, and durability testing to prepare them for human testing in the next five years. The penises are used with a donor penis and sanitized to expunge any donor cells and then the male patient’s own cells are grown in culture for four to six weeks and injected into the shaft — muscle and blood vessel cells and all. The trick is using a male’s own cells to dramatically decrease the risk of immunological rejection, which occurs when the body recognizes it as a foreign and dangerous invader.

“My concern is that they might struggle to recreate a natural erection,” Atala said. “Erectile function is a coordinated neurophysiological process starting in the brain, so I wonder if they can reproduce that function or whether this is just an aesthetic improvement. That will be their challenge.”

When first tested with genetically engineered penises in 2002, once the 18 rabbits recovered from their surgery, they attempted to have sex within 30 seconds of being placed in a cage with a female. Atala reported they were able to penetrate and produce sperm with their new generated penises, but at about the stamina and efficacy of a 60-year-old penis, versus their goal of a 30-year-old. Now with the advent of a nearly complete lab-generated penis, Atala and his team hope to achieve erections for sexual intercourse. What is the point of having a penis if you can’t fulfill the most fundamental and innate function of reproduction — arguably the reason for our existence?

“If we can engineer and replace this tissue, these men can have erections again,” said Dr. James Yoo, a collaborator of Atala’s at Wake Forest Institute, who is working on bioengineering and replacing parts of the penis to help treat erectile dysfunction. “As a scientist and clinician, it’s this possibility of pushing forward current treatment practice that really keeps you awake at night.”

Bacterial Gene Transfer Gets Sexier.

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Mycobacterium smegmatis can donate larger portions of its genome to other bacteria than previously thought, approaching the level of gene shuffling seen in sexual reproduction.

310mycobacteriaTB

n what appears to be a novel form of bacterial gene transfer, or conjugation, the microbeMycobacterium smegmatis can share multiple segments of DNA at once to fellow members of its species, according to a study published today (July 9) in PLOS Biology. The result: the generation of genetic diversity at a pace once believed to be reserved for sexual organisms.

“It is a very nice study providing clear evidence that, in Mycobacterium smegmatis at least, conjugation underlies much of species diversity,” said Richard Meyer, who studies conjugation at The University of Texas at Austin, in an email toThe Scientist.

Traditionally, transfer of genetic material through conjugation has been considered an incremental process. Plasmids mediate the transfer of short segments of DNA, one at a time, between pairs of touching bacterial cells, often conferring such traits as antibiotic resistance.

But M. smegmatis, a harmless bacterium related to the pathogen M. tuberculosis, appears to use a more extensive method of gene shuffling, endowing each recipient cell with a different combination of new genes. The researchers dubbed this form of conjugation “distributive conjugal transfer.” “We can generate a million [hybrid bacteria] overnight, and each of those million will be different than each other,” said coauthor Todd Gray, a geneticist at the New York State Department of Health’s Wadsworth Center.

Coauthor Keith Derbyshire, also a geneticist at the Wadsworth Center, and colleagues had previously published data indicating that M. smegmatis used a novel form of conjugation, but the new study confirms and expands on their suspicions using genetic data. The researchers compared the whole genome sequences of donor and recipient bacteria before and after the massive gene transfers.

The researchers found that, after the transfers, up to a quarter of the recipient bacteria’s genomes were made up of donated DNA, scattered through the chromosomes in segments of varying lengths.

According to the authors, the diversity resulting from distributive conjugal transfer approaches that achieved by meiosis, the process of cell division that underlies sexual reproduction. “The progeny were like meiotic blends,” said Derbyshire. “The genomes are totally mosaic.”

The genes and machinery behind distributive conjugal transfer remain largely unknown, but Gray, Derbyshire, and colleagues have zeroed in on a region of the genome that may determine whether a bacterium becomes a DNA donor or recipient. The region encodes the ESX-1 family of proteins, which are also involved in secreting molecules from M. tuberculosis that give the bacterium its pathogenicity.

The researchers suspect distributive conjugal transfer is important in multiple species of Mycobacteria. Earlier this year, Roland Brosch, a tuberculosis researcher at the Pasteur Institute in France, and colleagues sequenced various strains of the pathogenic M. canettii, which is closely related to M. tuberculosis, and found they were genetically variable—possible evidence of distributive conjugal transfer, according to Gray and Derbyshire. Brosch said he had not yet been able to demonstrate distributive conjugal transfer in M. canettii, however, and he noted that such large-scale gene transfer is unlikely to be occurring in M. tuberculosis, which is a highly genetically homogenous species that shows little sign of recent horizontal gene transfer.

Brosch agreed with Derbyshire and Gray that distributive conjugal transfer could have been important in the evolutionary history of the Mycobacteria genus as a whole, however.  Gray pointed out that understanding the prevalence of distributive conjugal transfer could change views on the time scale of mycobacterial evolution. “I think it’s really going to open some eyes about how quickly things can change,” he said.

Asked whether distributive conjugal transfer could be happening in bacteria outside of theMycobacterium genus, Derbyshire said it remained a mystery, but added: “It’s likely to be more prevalent than currently is known.”

T.A. Gray, “Distributive conjugal transfer in Mycobacteria generates progeny with meiotic-like genome-wide mosaicism, allowing mapping of a mating identity locus,” PLOS Biology, 11: e1001602, 2013.

Source: the-scientist.com

Tags

sexual reproduction , mycobacteria, DNA sequencing, diversity, conjugation, bacterial evolution andbacteria