Gene

• The world’s oldest conjoined twins, Lori and George Schappell, recently died, aged 62.
• Conjoined twins are incredibly rare, accounting for about one or two in every 100,000 births.
• Because conjoined twins are so rare, it is difficult to know exactly how they come about.

Types of conjoined twins

• There are 15 recognised types of conjoined twins, based on the various places their bodies fuse.
• Conjoined twins are usually picked up on routine ultrasound scans performed during pregnancy.
• Conjoined twins who are diagnosed by imaging are typically delivered by caesarean section.

Separating twins

• One of the longest operations to separate conjoined twins, who were fused at the cranium, took more than 100 hours.
• The earliest recorded attempt at surgical separation of conjoined twins dates back to AD945 in Armenia where conjoined brothers lived until middle age before one of them died.
• Separating conjoined twins requires a significant amount of planning before surgery can begin, including, of course, lots of imaging such as ultrasound, CT and MRI.
• Twins who share vital organs – or whose organs are fused – have a lower chance of a successful separation.

Adam Taylor does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

Orphan designation: branaplam Treatment of spinal muscular atrophy, 16/04/2018 Withdrawn

• They’ve now decided to freeze sperm from as many genetically diverse male African wild dogs as possible and use this to artificially inseminate female African wild dogs for the first time.
• Reproductive and molecular biologist Damien Paris explains why artificial breeding is the best and most economical way to ensure that genetically diverse wild dogs live on.

Why is the African wild dog in danger?

• They are highly efficient pack hunters but need large home ranges to survive and avoid competitors like lions.
• The problem is that most of the remaining habitats are so small and fragmented that they can’t support large populations anymore.
• Usually, when wild dogs are subadults (around two years old) they move far away and form their own pack.

How can genetic diversity help the African wild dog survive?

• Those diseases can spread rapidly among wild dogs and decimate a pack, which is about five to 20 dogs.
• In 2017, canine distemper virus completely wiped out 21 out of 22 packs of wild dogs in Laikipia County, Kenya in less than four weeks.
• We plan to use sperm freezing and artificial insemination to help distribute genetic diversity between isolated populations.

What conservation methods have been used before?

• To increase genetic diversity, African wild dogs have been translocated (moved) across South Africa since 1998.
• Over several weeks, they form a new genetically mixed pack that is released into the wild.
• A whole population of wild dogs could be lost with the next disease outbreak.

How will sperm freezing and artificial insemination help?

• Our back-up plan against disease outbreaks is to create a bank of African wild dog sperm from multiple males.
• Sperm frozen in liquid nitrogen tanks at very cold temperatures can last 50 or 100 years and still produce offspring.
• We recently improved the freezing technique so African wild dog sperm are now able to swim and survive for eight hours after being thawed.
• We plan to build a consortium so that we can have multiple sperm banks throughout South Africa as back-ups.

Will this be very expensive?

• Some recent modelling in other species found that the hybrid approach was between seven and 84 times cheaper than the natural breeding approach.
• This is because it needed 13-100 times fewer animals to maintain 90% genetic diversity in the population over a 100-year period.

Damien Boyd Bertrand Paul Paris receives funding from Morris Animal Foundation, Roger Willliams Park
Zoo and Fresno Chaffee Zoo. He is affiliated with James Cook University, the Institute for Breeding Rare and Endangered African Mammals, and is a Visiting Fellow of the Mammal Research Institute.

• The Company highlighted the distinct ability of its AURIGIN™ platform to identify both cell state plasticity, the proliferative state in which cancer cells grow, and the causative gene targets.
• In a second poster, Auron shared preclinical data from its program targeting KAT2A/B, an AURIGIN-identified histone acetyltransferase driving small cell lung cancer (SCLC), neuroendocrine prostate cancer (NEPC), and acute myeloid leukemia (AML).
• These data led to the nomination of AUTX-703, an orally available and selective KAT2A/B degrader development candidate, for which Auron expects to file an IND in 2024.
• “The understanding that cellular plasticity contributes to aggressive and treatment-resistant tumor growth underscores the need for innovative, targeted approaches.